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LEGI-SLATE Report for the 106th Congress     Mon, August 16, 1999  8:00am (EDT) 
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           Q U I C K   F E D E R A L   R E G I S T E R  ( T E X T )             
                                  On 09/30/94                                   
                                                                                
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On 09/30/94                                                                     
[L-S document 503718, 59 FR 50042, 4476 lines]                                  
                                                                                
  ENVIRONMENTAL PROTECTION AGENCY                                               
                                                                                
  40 CFR Parts 9, 86 and 88                                                     
                                                                                
  [AMS-FRL-5002-7]                                                              
                                                                                
  Emission Standards for Clean-Fuel Vehicles and Engines, Requirements for      
  Clean-Fuel Vehicle Conversions, and California Pilot Test Program             
                                                                                
  AGENCY: Environmental Protection Agency (EPA).                                
                                                                                
  ACTION: Final rule.                                                           
                                                                                
  ----------------------------------------------------------------------------- 
                                                                                
  SUMMARY: The 1990 Clean Air Act Amendments require the establishment of two   
  clean-fuel vehicle programs: a Clean Fuel Fleet Program and a California      
  Pilot Test Program. Under the Clean Fuel Fleet Program, a percentage of new   
  vehicles acquired by certain fleet owners located in covered areas will be    
  required to meet clean-fuel fleet vehicle emission standards. Fleet owners    
  can comply with this requirement by purchasing new clean-fuel fleet vehicles, 
  by converting conventional vehicles to clean-fuel fleet vehicles, or by       
  acquiring "credits" pursuant to a credits program. Affected states are        
  required to revise their State Implementation Plans to implement the fleet    
  program, including provisions to implement a credit program and exempt clean- 
  fuel fleet vehicles from certain transportation control measures. Regulations 
  have already been promulgated for the credit program and transportation       
  control measures exemptions. Also, definitions of terms used with the Clean   
  Fuel Fleet program have recently been finalized. The other Clean Air Act      
  clean-fuel vehicle program is the California Pilot Test program. This program 
  requires manufacturers to sell light-duty clean-fuel vehicles in the state of 
  California. EPA has established a credit program for the California Pilot     
  Test Program in a separate rulemaking.                                        
                                                                                
    This action promulgates the statutory requirements that have not been       
  implemented to date. These include the emission standards for light-duty and  
  heavy-duty clean-fuel vehicles, regulations for the conversion of             
  conventional vehicles to clean-fuel fleet vehicles, manufacturer California   
  clean-fuel vehicles sales requirements under the California Pilot Test        
  Program, and a state opt-in program for the California Pilot Test Program.    
  The part of the conversion provisions addressing the sales volume limit       
  beyond which special small-volume manufacturer provisions will not apply,     
  will not become effective sooner than 60 days after publication and then only 
  if no adverse comment is received within 30 days of publication. If adverse   
  comment is received within 30 days of publication, EPA will withdraw this     
  part of the rule pending a full notice and comment process on this topic.     
                                                                                
  DATES: This regulation is effective October 31, 1994, except that 40 CFR      
  88.306-94(b)(3) will become effective on November 29, 1994, unless notice is  
  received on or before October 31, 1994, that adverse or critical comments     
  will be submitted. EPA will publish a timely document in the Federal Register 
  if the effective date is delayed for this reason. The effective date may also 
  be delayed if the information collection requirements contained in this       
  section have not been approved by the Office of Management and Budget. In     
  that case, EPA will publish a timely document in the Federal Register         
  delaying the effective date. The incorporation by reference of certain        
  publications listed in the regulations is approved by the Director of the     
  Federal Register as of October 31, 1994, except as specified elsewhere in     
  this DATES section. Sections 40 CFR 88.104-94 (b) and (d), 88.201-94 through  
  88.206-94, and 88.306-94(b) (1), (2), and (4) are not effective until the     
  Office of Management and Budget approves the information collection           
  requirements contained in them. EPA will publish a document in the Federal    
  Register once the information collection requirements are approved.           
                                                                                
  ADDRESSES: Comments on 40 CFR 88.306-94(b)(3) may be submitted to Docket No.  
  A-92-30 at the following address. Materials relevant to this proposal have    
  been placed in Docket Nos. A-92-30 (Clean Fuel Fleet Program) and A-92-69     
  (California Pilot Test Program) by EPA. The docket is located at: Air and     
  Radiation Docket and Information Center, Room M-1500, Waterside Mall, U.S.    
  Environmental Protection Agency, 401 M Street SW., Washington, DC 20460.      
  These dockets may be inspected between 8:30 a.m. and noon, and between 1:30   
  and 3:30 p.m. on weekdays. EPA may charge a reasonable fee for copying docket 
  materials. In addition, copies of the Summary and Analysis of Comments        
  document, which develops certain issues relevant to this final rulemaking,    
  may be obtained by request from the contact person below. This document       
  contains the Agency's response to the public comments received in regard to   
  the two Notices of Proposed Rulemaking (NPRM).                                
    Electronic copies of the preamble, regulations, Regulatory Impact Analysis, 
  Regulatory Support Document for heavy-duty clean-fuel vehicles, and the       
  Summary and Analysis of Comments for this rulemaking are available on the     
  Office of Air Quality Planning and Standards (OAQPS) Technology Transfer      
  Network Bulletin Board System (TTNBBS). Instructions for accessing TTNBBS and 
  downloading the above rulemaking files are described under SUPPLEMENTARY      
  INFORMATION in section I.A.                                                   
                                                                                
  FOR FURTHER INFORMATION CONTACT: Mr. Bryan Manning, U.S. EPA (SRPB-12),       
  Regulatory Development and Support Division, 2565 Plymouth Rd, Ann Arbor, MI  
  48105. Telephone (313) 741-7832.                                              
                                                                                
  SUPPLEMENTARY INFORMATION:                                                    
                                                                                
  I. Introduction                                                               
                                                                                
  A. Accessing Electronic Copies of Rulemaking Documents through the Technology 
  Transfer Network Bulletin Board System (TTNBBS)                               
                                                                                
    TTNBBS can be accessed using a dial-in telephone line (919-541-5742) and a  
  1200, 2400, 9600, or 14,400 bps modem. The parity of the modem should be set  
  to N or none, the data bits to 8, and the stop bits to 1. When first signing  
  on to the bulletin board, the user will be required to answer some basic      
  informational questions to register into the system. After registering,       
  proceed through the following options from a series of menus:                 
                                                                                
  OMS;                                                                          
  Rulemaking and Reporting;                                                     
  Alternative Fuels/Fleets;                                                     
  Clean Fuel Fleets or California Pilot Program.                                
                                                                                
    A list of ".ZIP" files will be displayed, all of which relate to the Clean  
  Fuel Fleet or California Pilot Program rulemakings. The above five documents  
  for the Emission Standards for Clean-Fuel Vehicles and Engines, Requirements  
  for Clean-Fuel Vehicle Conversions, and California Pilot Test Program         
  rulemaking will be listed in the form of ".ZIP" files and are identified by   
  the following titles:                                                         
                                                                                
  "CFF-PRE.ZIP" (Preamble)                                                      
  "CFF-REG.ZIP" (Regulations)                                                   
  "CFF-COM.ZIP" (Summary and Analysis of Comments)                              
  "CFF-RIA.ZIP" (Regulatory Impact Analysis)                                    
  "CFF-RSD.ZIP" (Regulatory Support Document for heavy-duty CFVs)               
                                                                                
    To download these files, type the instructions below and transfer according 
  to the appropriate software on your computer: <D</=ownload, <P</=rotocol,     
  <E</=xamine, <N</=ew, <L</=ist, <H</=elp or <ENTER</= to exit: D filename.ZIP 
    The user needs to choose a file transfer protocol appropriate for the       
  user's computer from the options listed on the terminal. The user's computer  
  is then ready to receive the file by invoking the user's resident file        
  transfer software. Programs and instructions for de-archiving compressed      
  files can be found under <S</=ystems Utilities from the top menu, under       
  <A</=rchivers/de-archivers.                                                   
    TTNBBS is available 24 hours a day, 7 days a week except Monday morning     
  from 8-12 EST, when the system is down for maintenance and backup. For help   
  in accessing the system, call the systems operator at 919-541-5384 in         
  Research Triangle Park, North Carolina, during normal business hours EST.     
                                                                                
  B. Background                                                                 
                                                                                
    The Clean Air Act (CAA) Amendments of 1990 (Public Law 101-549) added part  
  C to Title II of the CAA entitled, "Clean Fuel Vehicles". Under part C,       
  states are to establish clean fuel fleet programs (collectively called the    
  Clean Fuel Fleet (or CFF) program) in certain nonattainment areas and EPA is  
  to establish a clean-fuel vehicle (CFV) pilot program in the State of         
  California (the California Pilot Test program or Pilot program).              
    The purpose of the Clean Fuel Fleet Program is to introduce light- and      
  heavy-duty CFVs in specified "covered areas" with air quality problems. CAA   
  section 246(a)(2) defines a "covered area" for purposes of the fleet program  
  as an area having a 1980 population of 250,000 or more that is also (1) a     
  serious, severe, or extreme ozone nonattainment area (based on 1987-1989      
  data), or (2) a carbon monoxide (CO) nonattainment area with a CO design      
  value at or above 16.0 parts per million (based on 1988-1989 data).           
  Currently, there are 22 such areas in 19 states (Table 1).                    
                                                                                
           Table 1.--States and Areas Affected by the Clean-Fuel Fleet          
                                     Program                                    
                                                                                
               Affected area                            State(s)                
                                                                                
   1. Atlanta                             Georgia.                              
   2. Baltimore                           Maryland.                             
   3. Baton Rouge                         Louisiana.                            
   4. Beaumont-Port Arthur                Texas.                                
   5. Boston-Lawrence-Worcester (Eastern  Massachusetts, New Hampshire.         
    Massachusetts)                                                              
   6. Chicago-Gary-Lake County            Illinois, Indiana.                    
   7. Denver-Boulder                      Colorado.                             
   8. El Paso                             Texas.                                
   9. Greater Connecticut                 Connecticut.                          
   10. Houston-Galveston-Brazoria         Texas.                                
   11. Los Angeles-South Coast Air Basin  California.                           
   12. Milwaukee-Racine                   Wisconsin.                            
   13. New York-Northern New Jersey-Long  Connecticut, New Jersey, New York.    
    Island                                                                      
   14. Philadelphia-Wilmington-Trenton    Delaware, Maryland, New Jersey,       
                                           Pennsylvania.                        
   15. Providence (All Rhode Island)      Rhode Island.                         
   16. Sacramento Metro                   California.                           
   17. San Diego                          California.                           
   18. San Joaquin Valley                 California.                           
   19. Southeast Desert Modified AQMA     California.                           
   20. Springfield (Western               Massachusetts.                        
    Massachusetts)                                                              
   21. Ventura County                     California.                           
   22. Washington (District of Columbia)  Maryland, Virginia, District of       
                                           Columbia.                            
                                                                                
    These states are required to revise their State Implementation Plans (SIPs) 
  to ensure that "covered fleet" owners will include, through purchase or       
  lease, a minimum percentage of CFVs among the new vehicles they purchase for  
  their fleets. (A "covered fleet" is defined in CAA section 241 as a fleet of  
  ten or more motor vehicles which are owned or operated, leased, or otherwise  
  controlled by a single person.) Both private business and government          
  (federal, state, and local) fleets are subject to the statute. However,       
  certain fleets and vehicles are exempt from the regulations, including fleets 
  with vehicles that cannot be fueled at a central location, vehicles that are  
  normally garaged at a personal residence, or vehicles that belong to vehicle  
  classes without applicable CFV standards. (See the Definitions Rule: 58 FR    
  64679, December 9, 1993). In their SIP revisions, states must include         
  provisions to require that CFVs used in the clean fuel fleet program operate  
  on fuels on which they comply with the CFV standards.                         
    Covered fleet operaters can also meet the requirements by converting        
  conventional vehicles to CFVs, or by obtaining credits. CAA section 246(a)(3) 
  requires that all states containing all or part of an ozone and/or CO         
  nonattainment area described above that is reclassified in the future as a    
  serious, severe, or extreme ozone nonattainment area, or has a CO design      
  value at or above 16.0 parts per million, must prepare revised SIPs           
  implementing the CFF program within one year of reclassification.             
    Three vehicle classes are included in the CFF program: light-duty vehicles  
  (LDVs) and light-duty trucks (LDTs) up to 8,500 lbs GVWR,/1/ and heavy-duty   
  vehicles (HDVs) between 8,500 lbs and 26,000 lbs GVWR./2/ To qualify as a     
  CFV, a vehicle must meet one of three sets of increasingly stringent          
  standards. These are referred to as low-emission vehicle (LEV) standards,     
  ultra low-emission vehicle (ULEV) standards, and zero-emission vehicle (ZEV)  
  standards.                                                                    
    Note /1/ Gross Vehicle Weight Rating.                                       
    Note /2/ HDVs over 26,000 lbs GVWR are not included in the mandatory        
  program.                                                                      
                                                                                
    CAA section 242(a) requires EPA to promulgate CFV emission standards for    
  purposes of compliance with the CFF program and the Pilot program (LEV        
  standards). In addition, section 246(f)(4) requires EPA to promulgate         
  emission standards for purposes of the CFF program credit program (ULEV and   
  ZEV standards). Under section 249(d)(3), the CFF credit program standards     
  will also apply to the Pilot credit program. Therefore, vehicles that meet    
  ULEV or ZEV standards are eligible for vehicle purchase credits under the CFF 
  program and for manufacturers' credits under the Pilot program.               
    The CAA Amendments of 1990 require EPA to promulgate a Pilot program for    
  the sale of CFVs in the State of California. Whereas the CFF program will be  
  run by individual states, the Pilot program is a federal program that will be 
  administered in California. Manufacturers with motor vehicle sales in         
  California are required to sell a minimum number of light-duty CFVs (CFVs up  
  to 8,500 lbs. GVWR) in California on an annual basis. Manufacturers may meet  
  their share of required sales by selling the required number of CFVs or by    
  using earned credits or credits they have acquired from other manufacturers.  
  (EPA established the credits program in a previous rulemaking (57 FR 60038;   
  December 17, 1992)). To earn credits, a manufacturer may sell more CFVs than  
  required or sell CFVs which meet stricter exhaust emission standards. Except  
  for heavy LDTs, for model years 1996 through 2001, the compliance standards   
  for the Pilot program are known as the TLEV standards and credits are         
  available for LEV, ULEV and ZEV purchases. Beginning in 2001, the compliance  
  vehicle shifts to the LEV standards, and credits are only available for ULEV  
  and ZEV purchases. This provision commences in the 1998 model year for heavy  
  LDTs.                                                                         
    The CAA also directs EPA to establish a voluntary opt in program for states 
  that want to adopt the Pilot program. States which contain all or part of any 
  ozone nonattainment areas classified under subpart D of Title II as serious,  
  severe, or extreme are eligible to participate. To do so, states are to       
  revise their state implementation plans (SIPs) to include incentives for the  
  sale and use of CFVs as well as the production and distribution of clean      
  alternative fuels. States may not establish CFV sales or production mandates, 
  however.                                                                      
    The remainder of today's action covers light- and heavy-duty CFV exhaust    
  emission standards, requirements for vehicle conversions to CFVs, and the     
  Pilot program, as well as regulatory impacts of the CFF and Pilot programs.   
  In addition, EPA has included several technical amendments and clarifications 
  related to the Definitions rule (58 FR 64679) and the rulemaking for the CFF  
  credits program and transportation control measure exemptions (58 FR 11888;   
  March 1, 1993).                                                               
                                                                                
  II. Description of Action                                                     
                                                                                
  A. Clean-Fuel Vehicle Emission Standards                                      
                                                                                
    CAA section 242 requires EPA to promulgate regulations setting emission     
  standards and other requirements for CFVs. For LDVs and LDTs, EPA is required 
  to adopt the standards set forth in sections 242 and 243 unless it finds that 
  the standards of the California Air Resources Board LEV program are, in the   
  aggregate, at least as protective of public health and welfare as the federal 
  standards that would apply to CFVs. EPA cannot make such a finding at this    
  time so today's regulations adopt the standards set forth in the CAA.         
                                                                                
  1. Light-Duty Vehicle and Light-Duty Truck Clean-Fuel Vehicle Standards       
                                                                                
    a. Requirements of the CAA. Clean Air Act section 241(7) defines a CFV as a 
  vehicle that meets the emission standards applicable under part C of Title II 
  of the CAA. As discussed later in this preamble, CFVs will satisfy the        
  requirements of both the Pilot program and the CFF program. The CFV emission  
  standards for LDVs and LDTs are set forth in sections 242 and 243. (Standards 
  for heavy-duty CFVs under section 245 of the Act are discussed in II.A.2      
  below.) Any LDV, LDT, or HDV that can operate on only one fuel and that meets 
  these standards will be classified as a CFV regardless of the fuel that is    
  used to meet the CFV standards. However, a CFV in the CFF program must        
  operate on clean alternative fuels, as defined in section 241(2) of the Act,  
  when operating in the covered area.                                           
    Subsections 243(a) through (d) specify LDV and LDT exhaust emission         
  standards (50K and 100K miles) /3/ for the following pollutants: non-methane  
  organic gas (NMOG), carbon monoxide (CO), oxides of nitrogen (NOX), diesel    
  particulate matter (PM) (only for the 100,000 mile point), and formaldehyde   
  (HCHO). These standards are prescribed in two phases for LDVs and light LDTs  
  (up to 5,750 pounds loaded vehicle weight (LVW) and 6,000 pounds GVWR). Phase 
  I applies only to the Pilot program and takes effect with the 1996 model year 
  (MY), the first year of required sales under the Pilot program. These         
  statutory Phase I standards are numerically identical to those which define   
  the California Transitional Low Emission Vehicle (TLEV)./4/ The Phase I       
  standards apply to the Pilot program in MYs 1996 through 2001. Phase II       
  standards are identical to those which define the California Low Emission     
  Vehicle (LEV)./5/ The Phase II standards apply to the CFF program in MY 1998  
  and to the Pilot program beginning in MY 2001. Only one set of exhaust        
  emission standards applies to heavy LDTs (above 6,000 lbs. GVWR). These       
  standards take effect in MY 1998 and apply to both the CFF and the Pilot      
  program. Table 2 contains the TLEV and LEV standards for LDV and LDT CFVs.    
    Note /3/ The intermediate useful life for LDV and LDTs is 50,000 (50K)      
  miles. The full useful life for such vehicles is 100,000 (100K) miles.        
    Note /4/ The California TLEV standards are effective in model years 1994    
  through 1996.                                                                 
    Note /5/ The California LEV standards are effective in model years 1997     
  through 2003.                                                                 
                                                                                
    CAA part C section 241 specifies that definitions contained in part A,      
  section 216, shall apply to the CFV programs. The heavy LDT subcategories     
  (i.e., above 6,000 lbs. GVWR) shown in Table 2 are based on test weight. CAA  
  section 216(8) defines "test weight", or "TW", as the sum of the curb weight  
  and the GVWR divided by two:                                                  
                                                                                
  TW = (Curb weight + GVWR)/2 = ALVW                                            
                                                                                
  This definition was established in 40 CFR 86.129-94 by the federal Tier 1     
  rulemaking (56 FR 25724; June 5, 1991) and is referred to as "adjusted loaded 
  vehicle weight", or "ALVW". The Agency chose to use ALVW, as opposed to TW,   
  to minimize confusion with the term "equivalent test weight", which is used   
  interchangeably with "test weight" throughout current EPA motor vehicle       
  regulations and test procedures. Therefore, "test weight" defined in CAA      
  section 216(8) is referred to as ALVW in this Final Rule, which is consistent 
  with its definition established in the Tier 1 regulations.                    
                                                                                
        Table 2.-- Phase I and II LDV and LDT Clean Fuel Vehicle Emission       
                                    Standards                                   
                                                                                
                                                   Pollutant (grams/mile)       
                                                                                
         Standards (Effective Dates)          NMOG   CO     NOX    HCHO   PM/1/ 
                                                                                
  All LDVs; LDTs </=3750 lbs LVW; </=6000                                       
   lbs GVWR:                                                                    
                                                                                
  Phase I (1996 MY):                                                            
                                                                                
    50,000 miles                              0.125  3.4      0.4  0.015    ... 
    100,000 miles                             0.156  4.2      0.6  0.018   0.08 
                                                                                
  Phase II (1998 MY for CFFP; 2001 MY for Pilot program):                       
                                                                                
    50,000 miles                              0.075  3.4      0.2  0.015    ... 
    100,000 miles                             0.090  4.2      0.3  0.018   0.08 
  LDTs </=3750 and </=K5750 lbs LVW; </=6000                                    
   lbs GVWR:                                                                    
                                                                                
  Phase I (1996 MY):                                                            
                                                                                
    50,000 miles                              0.160  4.4      0.7  0.018    ... 
    100,000 miles                             0.200  5.5      0.9  0.023   0.08 
                                                                                
  Phase II (1998 MY for CFFP; 2001 MY for Pilot program):                       
                                                                                
    50,000 miles                              0.100  4.4      0.4  0.018    ... 
    100,000 miles                             0.130  5.5      0.5  0.023   0.08 
                                                                                
  LDTs </=6000 lbs GVWR (1998 MY):                                              
   </=3750 lbs ALVW:                                                            
    50,000 miles                              0.125  3.4   /2/0.4  0.015    ... 
    120,000 miles                             0.180  5.0      0.6  0.022   0.08 
   3750< LDTs </=65750 lbs ALVW:                                                
    50,000 miles                              0.160  4.4  /2/ 0.7  0.018    ... 
    120,000 miles                             0.230  6.4      1.0  0.027   0.10 
   5750< LDTs </=8500 lbs ALVW: /3/                                             
    50,000 miles                              0.195  5.0   /2/1.1  0.022    ... 
    120,000 miles                             0.280  7.3      1.5  0.032   0.12 
                                                                                
  /1/ Applicable to diesel-fueled vehicles only.                                
                                                                                
  /2/ Standards not applicable to diesel-fueled vehicles.                       
                                                                                
  /3/ Option of certifying HDEs in vehicles up to 10,000 lbs GVWR using the LDT 
  standards.                                                                    
                                                                                
    CAA section 242(c) lists the useful life and in-use testing limitations for 
  purposes of determining in-use compliance with the standards in section 243.  
  The useful life for CFVs is the same as adopted in EPA's regulations for 1994 
  and later model year LDVs and LDTs, commonly called Tier 1 standards (56 FR   
  25724, June 5, 1991). For LDVs and LDTs, the standards in section 243 are     
  established at the intermediate useful life of five years or 50,000 miles     
  (5/50,000), whichever occurs first, and a full useful life of 10 years or     
  100,000 miles (10/100,000), whichever occurs first (see Table 2). With        
  respect to in-use testing, however, section 242(c) provides that such testing 
  for these vehicle classes would not be done beyond seven years or 75,000      
  miles, whichever occurs first. The analogous intermediate and full useful     
  life levels for heavy LDTs are 5/50,000 and 11/120,000, respectively (see     
  Table 2). Similarly, section 242(c) provides that the in-use testing for      
  these vehicles would not be done beyond seven years or 90,000 miles,          
  whichever occurs first.                                                       
    While the standards described above apply to single fuel CFVs, subsection   
  243(d) also establishes different CFV NMOG standards for dual and flexible    
  fuel LDVs and LDTs./6/ These vehicles are to be certified to two sets of NMOG 
  standards (Table 3). One set contains the same NMOG levels that apply to      
  single fuel CFVs; dual and flexible fuel vehicles must meet this standard     
  when operating on the clean alternative fuel on which they are certified      
  (section 243(d)(2)). The second set of NMOG standards applies to flexible and 
  dual fuel vehicles when operated on conventional fuel for which they are      
  certified (section 243(d)(3))./7/ This second set of standards is, in effect, 
  equivalent to the next less stringent set of standards for the applicable     
  vehicle category and model year. For example, the Phase I NMOG standard for   
  flexible or dual fuel CFVs using conventional fuel is equivalent to the Tier  
  I non-methane hydrocarbon (NMHC) emissions standard./8/ The Phase II NMOG     
  standard for flexible or dual fuel CFVs using conventional fuel is equivalent 
  to the Phase I standard for single fuel CFVs. The NMOG standards for flexible 
  and dual fuel vehicles are listed in Table 3. Flexible or dual fuel vehicles  
  must comply with all other CFV exhaust standards shown in Table 2 and with    
  all other applicable requirements of Title II.                                
    Note /6/ Dual fuel vehicle is defined as any motor vehicle or motor vehicle 
  engine engineered and designed to be operated on two different fuels, but not 
  on a mixture of the fuels. The term "bi-fuel" is often used for this type of  
  design. Flexible fuel vehicle is defined as any motor vehicle or motor        
  vehicle engine engineered and designed to be operated on any mixture of two   
  or more different fuels. The term "variable-fuel" is often used for this type 
  of design. These definitions are contained in section Sec. 88.102-94 of the   
  regulatory text.                                                              
    Note /7/ CAA section 241 requires that dual and flexible fuel vehicles are  
  to operate on the fuels on which they are certified. As discussed in the CFF  
  credit program and TCM exemptions rulemaking (58 FR 11888, March 1, 1993),    
  dual and flexible fuel vehicles shall operate only on the clean alternative   
  fuel on which they are certified to the CFV standards when operating in a     
  covered area, as provided in section 246(a)(2).                               
    Note /8/ NMOG and NMHC emissions are essentially equivalent when the fuel   
  combusted is conventional gasoline.                                           
                                                                                
                Table 3.--NMOG Standards for Flexible- and Dual-                
                                 Fueled Vehicles                                
                                                                                
                                                Standard/1/ (g/mi)              
                                                                                
                   Vehicle subclass           50,000mi     100,000mi            
                                                                                
            LDVs, LDTs (</=6000 lbs GVWR):                                      
                                                                                
            Beginning MY 1996 for Pilot program:                                
                                                                                
              LDTs (0-3,750 lbs. LVW), LDTs   0.125/0.25   0.156/0.31           
              LDTs (3,751-5,750 lbs. LVW)     0.160/0.32   0.200/0.40           
                                                                                
            Beginning MY 1998 for CFFP; MY 2001 for Pilot program:              
                                                                                
              LDTs (0-3,750 lbs. LVW), LDVs  0.075/0.125  0.090/0.156           
              LDTs (3,751-5,750 lbs. LVW)    0.100/0.160  0.130/0.200           
            LDTs (</=6,000 lbs GVWR):                                           
                                                                                
            Beginning MY 1998:                                                  
                                                                                
              LDTs (0-3,750 lbs. ALVW)        0.125/0.25   0.180/0.36           
              LDTs (3,751-5,750 lbs. ALVW)    0.160/0.32   0.230/0.46           
              LDTs (</=5,750 lbs. ALVW)       0.195/0.39   0.280/0.56           
                                                                                
            /1/ The standards are presented for flexible- and dual-             
            fueled CFVs when operating on clean alternative fuel and            
            conventional fuel in the format "x/y" where x represents            
            the NMOG standard when the vehicle is operated on a clean           
            alternative fuel and y represents the NMOG standard when            
            the vehicle is operated on a conventional fuel.                     
                                                                                
    CAA section 246(f)(4) directs EPA to establish additional CFV standards for 
  ULEVs and ZEVs (discussed earlier). These standards, shown in Table 4, should 
  be more stringent than the CFV standards in section 243. Vehicles meeting     
  these more stringent standards are eligible to earn credits which may be used 
  toward compliance under the CFF program or the Pilot program, as specified in 
  sections 246(f) and 249(d)(3), respectively. The Act requires EPA to set      
  these more stringent standards for LDVs and LDTs so that they conform "as     
  closely as possible" to the ULEV and ZEV standards established by California  
  for vehicles in the same class. The California ULEV and ZEV standards are     
  described below in section A.1.b. in this preamble.                           
                                                                                
        Table 4.--LDV and LDT Clean Fuel Vehicle ULEV Emission Standards        
                                                                                
                                                    Pollutant (grams/mile)      
                                                                                
                                                                            PM  
               Vehicle category                NMOG   CO     NOX    HCHO   /1/  
                                                                                
  LDVs & LDTs </=3750 lbs LVW; </=6000 lbs                                      
   GVWR                                                                         
    50,000 miles                               0.040  1.7      0.2  0.008  0.08 
    100,000 miles                              0.055  2.1      0.3   .011  0.04 
  LDTs >3750 and </=5750 lbs LVW; </=6000 lbs                                   
   GVWR:                                                                        
    50,000 miles                               0.050  2.2      0.4  0.009  0.08 
    100,000 miles                              0.070  2.8      0.5  0.013  0.04 
  LDTs </=6000 lbs GVWR (1998 MY):                                              
   </=3750 lbs ALVW:                                                            
    50,000 miles                               0.075  1.7      0.2  0.008       
    120,000 miles                              0.107  2.5  /2/ 0.3  0.012  0.04 
  3750< LDTs </=5750 lbs ALVW:                                                  
    50,000 miles                               0.100  2.2      0.4  0.009       
    120,000 miles                              0.143  3.2  /2/ 0.5  0.013  0.05 
  5750< LDTs </=8500 lbs ALVW: /3/                                              
    50,000 miles                               0.117  2.5      0.6  0.011       
    120,000 miles                              0.167  3.7  /2/ 0.8  0.016  0.06 
                                                                                
  /1/ Applies to diesel vehicles only.                                          
                                                                                
  /2/ Does not apply to diesel vehicles.                                        
                                                                                
  /3/ Option of certifying HDEs in vehicles up to 10,000 lbs GVWR using the LDT 
  standards.                                                                    
                                                                                
    CAA section 242(b) states that CFVs up to 8,500 lbs. GVWR "shall comply     
  with all motor vehicle requirements of this title (i.e., on-board             
  diagnostics, evaporative emissions, etc.) which are applicable to             
  conventional gasoline-fueled vehicles of the same category and model year,    
  except as provided in section 244 with respect to administration and          
  enforcement, and except to the extent that any such requirement is in         
  conflict with the provisions of" part C. These include, but are not limited   
  to, standards for cold temperature CO exhaust emissions (cold CO), on-board   
  diagnostics (OBD), evaporative emission controls (evap), and onboard          
  refueling vapor recovery (ORVR). Previous requirements such as crankcase      
  controls and vehicle labeling also apply.                                     
    CAA section 243(e) directs EPA to apply the standards of the California Air 
  Resources Board (CARB) LEV program in lieu of the standards otherwise         
  applicable to CFVs under sections 242 and 243 if the CARB standards are, in   
  the aggregate, at least as protective of public health and welfare as the     
  federal standards that apply to CFVs. Section 243(e)(1) addresses the         
  replacement of CAA standards if CARB promulgates a single set of standards    
  while section 243(e)(2) addresses the replacement if CARB promulgates         
  multiple sets of standards. CARB's LEV program contains multiple sets of      
  standards to which vehicles can certify (i.e., LEV, ULEV, and ZEV);           
  therefore, section 243(e)(2) is the appropriate language for consideration    
  and is provided below:                                                        
                                                                                
    Section 243(e)(2): If the State of California promulgates regulations       
  establishing and implementing several different sets of standards applicable  
  in California pursuant to a waiver approved under section 209 to any category 
  of vehicles referred to in subsection (a), (b), (c), or (d) of this section   
  and each of such sets of California standards is, in the aggregate, at least  
  as protective of public health and welfare as the otherwise applicable        
  standards set forth in section 242 and subsection (a), (b), (c), or (d) of    
  this section, such standards shall be treated as 'qualifying California       
  standards' for purposes of this paragraph. Where more than one set of         
  qualifying standards are established and administered by the State of         
  California, the least stringent set of qualifying California standards shall  
  apply to the clean-fuel vehicles concerned in lieu of the standards otherwise 
  applicable to such vehicles under section 242 and this section.               
                                                                                
    EPA believes that the required comparison between the federal and CARB      
  standards is not limited to the CFV exhaust emission standards of sections    
  242 and 243 but must also include the other Title II standards referred to in 
  CAA section 242 (i.e., OBD, evap, etc.) and any California counterparts.      
  Thus, EPA is required to compare the standards in CAA sections 242(b) and 243 
  with the CARB standards to determine whether the CARB standards should        
  replace the federal standards.                                                
    As is discussed below in Section II.c., EPA cannot at this time make the    
  determination that each set of CARB standards is, in the aggregate, at least  
  as protective as the federal standards that apply to CFVs. Therefore, this    
  final rule promulgates the emission standards and requirements for CFVs found 
  in sections 242 and 243 of the CAA. EPA's reasoning to support this           
  conclusion is included in Section II.c.                                       
    Finally, CAA section 244 provides requirements regarding the administration 
  and enforcement of CFV exhaust emission standards. In the event that          
  numerical emission standards for CFVs up to 8,500 lbs. GVWR are the same      
  under the federal and California LEV program, EPA is to administer and        
  enforce those standards in the same manner and with the same flexibility as   
  CARB does under the California LEV program. This requires utilizing the same  
  interpretations and policy judgments including, but not limited to,           
  requirements regarding certification, production-line testing, and in-use     
  compliance. The application of California's administration and enforcement    
  practices does not depend on whether EPA replaces federal requirements with   
  California requirements under section 243(e). If the Administrator determines 
  that adopting California's administration and enforcement approaches would    
  not meet the criteria for a waiver under section 209, then federal            
  administration and enforcement procedures and interpretations would apply.    
    b. CARB's Low-Emission Vehicle Standards. Pursuant to CAA section 209, the  
  State of California applied to EPA for a waiver on October 4, 1991 for its    
  "Low-Emission Vehicle and Clean Fuels Regulations". EPA granted the waiver on 
  January 7, 1993 (58 FR 4166, January 13, 1993). (Although states are          
  generally preempted by CAA section 209 from adopting their own motor vehicle  
  standards, California may adopt its own standards provided that EPA waivers   
  the preemption provision of section 209.)                                     
    California's regulations establish four new levels of vehicle emission      
  standards, termed "vehicle emission categories", for LDVs, LDTs, and medium-  
  duty trucks (MDTs)./9/ These new standards are effective with 1994 model year 
  vehicles./10/ The California emission categories are, in order of increasing  
  stringency: TLEV (Transitional Low Emission Vehicle); LEV (Low Emission       
  Vehicle); ULEV (Ultra Low Emission Vehicle); and ZEV (Zero Emission Vehicle). 
  The TLEV exhaust emission standards for NMOG, CO, NOX, PM, and HCHO are       
  identical to the federal Phase I CFV standards described above. The LEV       
  exhaust emission standards are identical to the federal Phase II CFV          
  standards. The California ULEV and ZEV standards are the same as the federal  
  ULEV and ZEV categories, established for purposes of the CFF and Pilot        
  program credit programs. CARB defines a ZEV as:                               
                                                                                
    Note /9/ The medium-duty truck class is a vehicle class unique to CARB and  
  includes trucks between 6,000 and 14,000 lbs GVWR.                            
    Note /10/ See CARB's Proposed Regulations for Low-Emission Vehicles and     
  Clean Fuels, Staff Report, available in EPA Air Docket A-91-23.               
                                                                                
    * * * any vehicle which is certified * * * to produce zero emissions of any 
  criteria pollutants under any and all possible operational modes and          
  conditions. A ZEV may be equipped with a fuel fired heater provided that the  
  fuel fired heater cannot be operated at ambient temperatures above 40 degrees 
  Fahrenheit and the heater is demonstrated to have zero evaporative emissions  
  under any and all possible operational modes and conditions./11/              
    Note /11/ California Code of Regualtions, Title 13, Definitions Section,    
  Paragraph 15.                                                                 
                                                                                
    CARB is allowing the use of intermediate in-use compliance standards that   
  are intended to facilitate compliance by vehicle manufacturers. These in-use  
  standards are numerically half way between the certification standards of the 
  new emission category and the old emission category (e.g., half way between   
  TLEV and LEV standards). These intermediate standards will be effective       
  through MY 1995 for TLEVs and through MY 1998 for LEVs and ULEVs.             
    c. Comparison of CAA and CARB Requirements. As discussed above, CAA section 
  243(e) provides that CARB's standards shall replace the federal CFV and other 
  motor vehicle standards if the CARB standards are, in the aggregate, at least 
  as protective of public health and welfare as the CAA standards. While EPA    
  believes that Congress preferred that the statutory standards be replaced     
  with the CARB standards, EPA cannot at this time make the determination that  
  CARB standards are, in the aggregate, at least as protective as the federal   
  standards. Therefore, as mentioned earlier, EPA is at this time establishing  
  federal standards that will apply to CFVs in the CFF and Pilot program.       
    As stated in the proposal, EPA believes that section 243(e)(2) requires a   
  separate comparison of federal Phase I and Phase II standards to CARB         
  standards. For the least stringent set of federal CFV standards (the Phase I  
  standards), the appropriate comparison is to the least stringent set of       
  California CFV standards (the TLEV standards). Similarly, the appropriate     
  comparison for the federal Phase II standards is with the California LEV      
  standards.                                                                    
    The Phase I standards will apply to the Pilot program in the 1996 MY. The   
  phase II standards will apply to the CFF program in the 1998 MY, and to the   
  Pilot program in the 2001 MY. Therefore, the federal Phase I standards will   
  not apply to any federal CFV program after MY 2001. For this reason, EPA      
  considers the California LEV standards to be the least stringent set of       
  qualifying California standards after MY 2001, and currently intends to apply 
  the California LEV standard to the CFF and Pilot programs at that time if     
  replacement of the federal Phase II standards is warranted under section      
  243(e)(2). EPA requested comment in the proposal on this interpretation of    
  the CAA and no adverse comments were received.                                
    EPA must also compare CARB standards to the following federal requirements  
  that apply to CFVs to assess whether "each of such sets of California         
  standards is, in the aggregate, at least as protective" as the federal        
  standards: cold CO emissions, evaporative emissions, onboard refueling vapor  
  recovery, on-board diagnostics, total hydrocarbons, and non-methane           
  hydrocarbon standards. These standards are compared individually below.       
    i. Cold CO emissions. The currently waived California program does not have 
  a cold CO standard which corresponds to the federal cold CO standard. It is   
  not yet possible for EPA to consider CARB's cold CO standards in its          
  comparison of the respective mobile source programs since California has not  
  yet requested nor received a waiver.                                          
    In vehicles using liquid fuel, the difficult process of vaporizing cold     
  liquid fuel for combustion contributes significantly to cold start emissions. 
  Gasoline vehicles are most susceptible to this phenomenon in cold conditions. 
  On July 17, 1992, EPA promulgated a cold CO standard (57 FR 31888, 40 CFR     
  86.201) in order to control CO emissions from gasoline-powered vehicles when  
  operating in cold temperatures./12/ These regulations became effective for MY 
  1994. Although these regulations cover only gasoline-fueled vehicles, CAA     
  section 242(b) extends the regulations to all CFVs regardless of fuel type by 
  requiring that CFVs meet all federal requirements of Title II of the CAA that 
  apply to gasoline vehicles of the same category and model year.               
    Note /12/ CAA Section 202(j) contains provisions for cold CO requirements.  
                                                                                
    On January 14, 1993, CARB approved a cold CO standard which became          
  effective in September 1993. CARB's regulations include gasoline-fueled, LPG, 
  and alcohol-fueled vehicles, but do not cover other fuels. EPA is not able at 
  this time to consider the CARB cold CO regulations because CARB has not       
  requested nor received a waiver of federal preemption for its cold CO         
  requirements.                                                                 
    ii. Evaporative emissions. The currently waived CARB evaporative emission   
  standards and test procedures are not comparable to the recently promulgated  
  federal evaporative emission standards and test procedures. Current federal   
  regulations for evaporative emissions testing are effective through MY 1995,  
  after which new federal regulations will be phased in. California has two     
  sets of new evaporative emissions regulations: one set will be implemented    
  only for 10 percent of California's MY 1995 vehicles and the second set,      
  which CARB is in the process of finalizing at this time, will be phased in    
  beginning in MY 1996. Indications are that CARB will seek a waiver for their  
  1996 evaporative emission regulations once they are finalized. EPA cannot yet 
  consider CARB's revised evaporative emission regulations applicable to the    
  1995 and later model years because CARB has not yet received a waiver for     
  them.                                                                         
    iii. Refueling emissions. Based on the currently waived California program, 
  EPA cannot at this time conclude that CARB's refueling emission control       
  regulations are as stringent as the federal onboard refueling vapor recovery  
  (ORVR) standards. The currently waived California Program does not have a     
  mobile source component which addresses refueling emissions. Federal Title II 
  standards for ORVR will be required on certain vehicles beginning in MY 1998  
  (59 FR 16262; April 6, 1994)./13/ CARB, which currently requires the use of   
  Stage II vapor recovery equipment at most service stations in California, has 
  held two workshops to discuss the proper application of refueling control     
  (November 2, 1993 and March 15, 1994). CARB considered three options:         
  adopting the federal ORVR regulations,; adopting a California-specific ORVR   
  rule, test, or standard; or maintaining that California's current motor       
  vehicle control program is, in the aggregate, at least as protective as the   
  federal program notwithstanding the lack of ORVR controls. In a recent CARB   
  mailout (94-27) dated May 27, 1994, ARB staff announced their proposal to     
  allow the certification of ORVR-equipped vehicles for sale in California.     
  However, the ARB staff did not address the equipped vehicles for sale in      
  California. However, the ARB staff did not address the specific issue of      
  whether ARB will require ORVR controls for certification. California's final  
  determination regarding ORVR control must ultimately be approved by the Air   
  Resources Board.                                                              
    Note /13/ The phase-in schedule requires that ORVR standards apply to 40    
  percent of each manufacturer's LDV sales volume in MY 1998, 80 percent in     
  1999, and 100 percent in MY 2000. The same phase-in schedule applies to LDTs  
  up to 8,500 lbs. GVWR but will not begin until MY 2001 for LDTs up to 6,000   
  lbs. GVWR and in MY 2004 for LDTs between 6,001 and 8,500 lbs. GVWR. The      
  requirements do not apply to vehicles above 8,500 lbs. GVWR.                  
                                                                                
    EPA is likely to consider California's lack of an ORVR aspect of its        
  program in the next section 209 waiver proceeding for CARB regulations        
  applicable to model years 1998 and later. EPA will likely decide in that      
  context whether California's motor vehicle program absent ORVR is at least as 
  protective of California as the federal program.                              
    iv. Volatile organic compound emissions. EPA and California use different   
  approaches to regulate emissions of volatile organic compounds (VOCs) from    
  vehicles. Therefore, EPA believes it is useful to compare California VOC      
  emission standards to the analogous federal standards on a fuel-by-fuel       
  basis, as presented below. For gasoline- and diesel-fueled vehicles, EPA      
  concludes that the CARB VOC emission standards are individually at least as   
  stringent as the federal standards. However, EPA cannot make this comparison  
  for gaseous and alcohol fuels at this time because CARB has not yet finalized 
  RAFs (reactivity adjustment factors) for these fuels.                         
    v. Fuel-by-fuel comparison. As stated above, EPA and CARB use different     
  approaches to establish VOC emission standards. Traditionally, federal        
  organic emissions controls have been based on total hydrocarbon (THC)         
  emissions where mass of THC emissions is measured by a flame ionization       
  detector (FID), implicitly assuming that all hydrocarbon emissions behave     
  similarly with respect to ozone reactivity and FID response. This approach is 
  not used for methanol-fueled vehicles because emissions from these vehicles   
  consist primarily of methanol and formaldehyde, and a FID will only detect    
  about 70 to 80 percent of the methanol and very little of the formaldehyde.   
  For methanol-fueled vehicles, the methanol and formaldehyde emissions are     
  sampled separately and measured chromatographically while other emissions are 
  measured by a FID. The oxygen mass is factored out of the methanol and        
  formaldehyde emissions resulting in "equivalent hydrocarbon emissions", which 
  are then summed with the other FID-measured hydrocarbons to yield organic     
  material (or total) hydrocarbon equivalent (OMHCE or THCE) mass. A third      
  approach involves separately measuring methane and subtracting it from the    
  THC to result in a non-methane hydrocarbon (NMHC) mass. For methanol-fueled   
  vehicles, NMHC is equivalent to OMNMHCE (organic material non-methane         
  hydrocarbon equivalent) or NMHCE (non-methane hydrocarbon equivalent).        
    The CAA has established THC and NMHC exhaust emission standards for         
  conventional light-duty gasoline and diesel vehicles (0.41 g/mile for THC and 
  0.25 g/mile for NMHC). EPA has also established OMHCE and OMNMHCE standards   
  for methanol-fueled vehicles (0.41 and 0.25 g/mile, respectively), an NMHC    
  standard for CNG-fueled vehicles (0.25 g/mile), and THC and NMHC standards    
  for LPG-fueled vehicles identical to the gasoline THC and NMHC standards./14/ 
    Note /14/ EPA Gaseous Fuels Rule: "Standards for Emissions from Natural     
  Gas-Fueled, and Liquified Petroleum Gas-Fueled Motor Vehicles and Motor       
  Vehicle Engines and Certification Procedures for Aftermarket Conversion       
  Hardware." (Published in the Federal Register on September 21, 1994).         
                                                                                
    CARB measures VOC emissions as non-methane organic gases (NMOG). Under this 
  approach, the mass of each organic compound except methane is measured and    
  adjusted according to its ozone-forming reactivity relative to gasoline       
  emissions. The sum of these adjusted masses is the amount of NMOG emitted     
  from the vehicle. An alternative CARB NMOG method involves measuring the      
  total mass of organic emissions and multiplying this mass by a single RAF for 
  the particular fuel used. A RAF is equivalent to the ratio of the ozone-      
  forming potential of emissions from a given fuel and the ozone-forming        
  potential of conventional gasoline emissions. CARB determines a RAF for each  
  fuel. Therefore, the relative stringency of the CARB and EPA standards for    
  organic emissions should be compared for each fuel individually.              
                                                                                
  Gasoline and Diesel Fuel                                                      
                                                                                
    For gasoline- and diesel-fueled vehicles, NMHC and NMOG standards are       
  equivalent since CARB has established a RAF of 1.0 for these fuels. In        
  addition, since the methane fraction of the THC emissions from these vehicles 
  is very low,/15/ and since CARB's TLEV and LEV NMOG standards (.125 and .075  
  g/mile, respectively) are well below the federal THC standard (0.41 g/mile),  
  vehicles designed to meet the CARB NMOG standard will not exceed the federal  
  THC standard. Thus, for gasoline- and diesel-fueled vehicles, the CARB NMOG   
  standards are at least as stringent as the federal THC and NMHC standards.    
    Note /15/ U.S. Environmental Protection Agency, Office of Mobile Sources,   
  "Specifications for S.A.I. Runs," Memorandum from Chris Lindhjem, Penny       
  Carey, and Joe Somers to the Record, April 24, 1992.                          
                                                                                
  CNG Fuel                                                                      
                                                                                
    The equivalency of CARB's NMOG standard with the federal NMHC standards     
  cannot be strictly determined at this point for natural gas vehicles since    
  CARB has not finalized a RAF for natural gas. Indications are that CARB may   
  enact a CNG RAF between 0.5 and 0.6. If CARB adopts a RAF of 0.5 or more,     
  then EPA expects that the CARB TLEV NMOG standard of 0.125 grams/mile         
  (representing the least stringent set of CARB standards) will be at least as  
  stringent as the 0.25 grams/mile federal NMHC standard. A RAF of 0.3 or more  
  would make the CARB LEV NMOG standard of 0.075 grams/mile equivalent to the   
  federal NMHC standard.                                                        
    CNG vehicles being certified as CFVs for use in the CFF and Pilot program   
  will not be subject to the federal THC standard, therefore, a comparison of   
  the relative stringency between the federal THC and the CARB NMOG standard is 
  not appropriate. In the Pilot program NPRM (58 FR 34727, June 29, 1993), EPA  
  requested comment on the appropriateness of applying a THC standard to        
  natural gas CFVs even though a THC standard is not applied to other natural   
  gas vehicles. EPA believes that requiring CNG vehicles to meet the federal    
  THC standard would exclude CNG vehicles from participating in the CFF and     
  Pilot programs. CNG vehicles do produce high methane emissions; however,      
  these emissions have a very low ozone reactivity and are therefore not a      
  significant contributor to ozone formation, which is a primary objective of   
  both programs./16/ In addition, CNG vehicles typically produce lower NMHC     
  emissions than gasoline-fueled vehicles. Therefore, although a THC standard   
  would strictly limit the amount of methane emissions a CNG vehicle could      
  emit, this result would be contrary to the ozone-reduction goals of the       
  programs when methane reactivity and lower NMHC emissions of CNG vehicles     
  relative to gasoline-fueled vehicles are considered. A further consideration  
  in deciding whether to apply a THC standard to CNG CFVs was the Agency's      
  desire to maintain consistency with its Gaseous Fuels rule whenever possible; 
  that rule also does not apply THC standards to CNG vehicles. Commenters were  
  not supportive of CNG vehicles, including CFVs, being subject to a THC        
  standard.                                                                     
    Note /16/ See CAA sections 246, 247, and 248.                               
                                                                                
  LPG Fuel                                                                      
                                                                                
    CARB has not finalized a RAF for LPG fuel. Therefore, EPA cannot at this    
  time strictly compare the CARB NMOG standard to the federal NMHC standard for 
  LPG vehicles. However, as with CNG, if CARB adopts a RAF of at least 0.5, EPA 
  expects that the CARB TLEV and LEV NMOG standard will be individually at      
  least as stringent as the federal NMHC standard.                              
                                                                                
  Alcohol Fuels                                                                 
                                                                                
    CARB has finalized a RAF of 0.41 for M85 vehicles and EPA's analysis        
  indicates that the CARB NMOG standard is individually as protective as the    
  federal NMHC equivalent standard for M85 fuel. However, CARB has not          
  established a RAF for E85 and M100 fuel. EPA thus cannot determine at this    
  time whether the CARB NMOG standards are individually as protective of public 
  health and welfare as the federal NMHC equivalent standards for all alcohol-  
  fueled vehicles.                                                              
    Regarding THC, methane emissions from alcohol-fueled vehicles, as with      
  gasoline- and diesel-fueled vehicles, are generally low enough that vehicles  
  meeting the CARB NMOG standards would also comply with the federal THC        
  standards. Therefore, EPA concludes that the CARB NMOG standards are          
  individually at least as stringent as the federal THC standard.               
    vi. Onboard diagnostics. The currently waived California onboard diagnostic 
  I (OBD I) regulation is not comparable to the recently promulgated federal    
  OBD regulation ( 58 FR 9468, February 19, 1993). The recently promulgated     
  federal OBD regulation is comparable to the recently revised California OBD   
  II regulation. In fact, EPA has decided that vehicles demonstrating           
  compliance with CARB onboard diagnostic (OBD) regulations will be deemed to   
  satisfy federal OBD requirements through the 1998 model year. However, EPA    
  cannot properly consider California's OBD II regulations under section 243(e) 
  of the CAA because California has not yet received a waiver of federal        
  preemption for them. Thus, in subsequent model years after 1998, vehicle OBD  
  systems must comply with the federal OBD requirements.                        
    vii. Summary. While the basic CFV exhaust standards are identical to CARB   
  standards, EPA is not able to find that each set of currently waived CARB     
  standards are as protective as the federal standards. By comparison to the    
  federal program established for CFVs today pursuant to section 242 and 243,   
  the California program lacks comparable components for at least the federal   
  cold CO standards, recently promulgated evaporative emission standards and    
  on-board diagnostics, as well as mobile source control for vehicle refueling  
  vapor recovery. Since EPA cannot at this time make the required determination 
  under section 243(e)(2), EPA is promulgating federal standards and            
  requirements in this final rule that will apply to CFVs. The CAA exhaust      
  standards will apply to clean fuel vehicles, and will be administered and     
  enforced according to CARB practices under CAA section 244, which is          
  discussed later under "Administration and Enforcement".                       
    Pursuant to section 242(b), federal requirements for cold CO, evaporative   
  emissions, refueling emissions, OBD (onboard diagnostics), NMHC, and, with    
  certain exceptions, THC will also apply to CFVs. As proposed, EPA is waiving  
  testing requirements for the cold CO standards for gaseous-fueled, diesel-    
  fueled and electric CFVs when manufacturers demonstrate compliance with the   
  cold CO standard through engineering analysis or test data./17/ EPA does not  
  expect problematic cold temperature CO emissions from gaseous-fueled CFVs     
  since they do not generally use fuel enrichment strategies to aid with cold   
  starts. Because of efficient combustion in diesel-fueled vehicles and the     
  minimal emissions inherent with electric vehicles, EPA does not expect        
  problematic cold CO emissions from these vehicles either. Also as discussed   
  above, EPA will not require CNG vehicles to meet the THC standard due to the  
  conflict with provisions of part C of the Act and other factors.              
    Note /17/ This provision is similar to the requirements for Otto-cycle      
  vehicles which must show compliance with a PM standard in the Tier 1          
  rulemaking (56 FR 25730).                                                     
                                                                                
    In the NPRM, EPA had anticipated that the regulatory processes underway     
  would allow EPA to conclude at the time of this final rule that each set of   
  California standards is, in the aggregate, at least as protective of public   
  health and welfare as the otherwise applicable standards set forth in section 
  242 and 243. The Agency still believes that such a conclusion may be possible 
  in the future. EPA will continue to monitor developments on these issues and, 
  if changing circumstances warrant, EPA intends to revisit this rule and       
  propose replacing the federal CFV standards with CARB standards under section 
  243(e)(2). In such a situation, the Agency will supplement the record and     
  provide an opportunity for comment as appropriate.                            
    d. Credit Generating Standards. As mentioned previously, the CAA requires   
  EPA to establish standards for Ultra-Low Emission Vehicles (ULEVs) and Zero   
  Emission Vehicles (ZEVs) which are more stringent than the standards that     
  otherwise apply to CFVs. Section 246(f)(4) of the CAA states that, "[t]he     
  standards established by the Administrator under this paragraph for vehicles  
  under 8,500 lbs. GVWR or greater shall conform as closely as possible to      
  standards which are established by the State of California for ULEV and ZEV   
  vehicles in the same class". As proposed, EPA is promulgating the ULEV and    
  ZEV standards established by CARB in the California LEV program as the        
  federal ULEV and ZEV standards. Section 249(d)(3) specifies that these and    
  other requirements established for purposes of the credit program for the     
  Clean Fuel Fleet program shall also apply for purposes of issuing credits in  
  the Pilot Program.                                                            
    A ZEV (e.g., an electric vehicle) is defined as a vehicle that complies     
  with the applicable ZEV standards (40 CFR 88.101). Like CARB, EPA will        
  determine compliance with the ZEV standard through engineering analysis       
  rather than by testing. As per section 244 of the CAA, the federal ZEV        
  standards will be administered and enforced in accordance with applicable     
  CARB procedures for LDVs and LDTs.                                            
    Consistent with the CARB, EPA is establishing ZEV standards which require   
  zero emissions of the following pollutants: NMOG, NOx, CO, particulates, and  
  HCHO. (Emissions from non-fuel sources, like tires, seats, paint, etc., will  
  likely exist as they do for conventional vehicles and other CFVs.) Compliance 
  with this requirement may be assessed through engineering analysis. This      
  analysis will include a description and analysis of all primary or auxiliary  
  equipment and engines which concludes that no emissions of the stated         
  pollutants is possible. The engineering analysis will determine that the      
  vehicle fuel system(s) does not contain either carbon or nitrogen compounds   
  (including air) which, when burned, form the above regulated exhaust          
  emissions. Such criteria will also assure that evaporative emissions will not 
  occur. Emission testing will not be necessary. When applicable, compliance    
  testing on ZEVs may be performed according to the testing requirements of CFR 
  Part 86 and 88 (Federal Test Procedure) at EPA's discretion. As with other    
  CFVs, ZEVs will be subject to the standards of part 88 which will be          
  administered per CARB's procedures for LDVs and LDTs and which are            
  incorporated by reference.                                                    
    Like CARB, EPA will consider a vehicle with an auxiliary heater to be a ZEV 
  if the heater will not operate at ambient temperatures above 40 degrees       
  Fahrenheit and the heater's power and/or fuel source does not have any        
  evaporative emissions in use. Commenters responding to this issue supported   
  this definition, on which EPA requrested comment in the NPRM. This auxiliary  
  heater will not be subject to the cold CO standard (contained in 40 CFR Part  
  86.201-94) because the cold CO regulations do not require the testing of      
  heaters. In addition, CARB has provided a specific exemption for ZEVs from    
  the CARB cold CO requirements (whether or not the vehicle is equipped with an 
  auxiliary heater); thus EPA's action on this issue is consistent with CARB's  
  approach. EPA may reconsider subjecting ZEV auxiliary heaters to the federal  
  cold CO requirement through regulation if circumstances warrant in the        
  future. Any vehicle with additional power system(s) or auxiliary engine(s)    
  that might produce regulated pollutants (e.g., a hybrid vehicle or electric   
  vehicle with an auxiliary power source to run other vehicle systems) will be  
  subject to the standards of 40 CFR Part 88 (administered per CARB procedures, 
  which are incorporated by reference) or future applicable regulations and     
  might not qualify as a ZEV. One respondent requested that EPA establish ZEV   
  exhaust emission standards above zero such that hybrid electric vehicles may  
  qualify as ZEVs. EPA has not promulgated a test procedure for such vehicles   
  and therefore standards have not been established.                            
    e. Administration and Enforcement Per California Practice. As proposed in   
  the NPRM, EPA will administer and enforce the numerical CFV exhaust emission  
  standards in the same manner as does the state of California. Section 244 of  
  the Act directs EPA to administer and enforce the numerical CFV emission      
  standards in the same manner as CARB does for vehicles less than 8,500 lbs.   
  GVWR. Specifically, section 244 states that when the applicable CAA and CARB  
  numerical standards are the same,                                             
                                                                                
    Such standards shall be administered and enforced by the Administrator (1)  
  in the same manner and with the same flexibility as the State of California   
  administers and enforces corresponding standards * * *; and (2) subject to    
  the same requirements, and utilizing the same interpretations and policy      
  judgments, as are applicable in the case of such CARB standards, including,   
  but not limited to, requirements regarding certification, production-line     
  testing, and in-use compliance.                                               
                                                                                
    The application of California administration and enforcement procedures     
  does not depend on whether EPA has replaced federal CFV standards with        
  California standards under section 243(e). Section 246(f)(4) provides that    
  the credit generating standards are to be administered and enforced in the    
  same manner as the other CFV standards. Therefore, EPA will administer and    
  enforce the ULEV and ZEV standards in the same manner as does CARB.           
    Section 244 states that EPA shall use California administration and         
  enforcement procedures unless EPA determines that doing so will not meet the  
  criteria for a waiver of preemption under section 209. EPA believes that the  
  application of current California procedures would meet the criteria for a    
  section 209 waiver. However, in a letter dated February 17, 1994, CARB        
  requested that EPA waive preemption under section 209 for certain proposed    
  amendments to California certification test procedures. EPA is currently      
  analyzing this waiver request to determine whether these test procedure       
  amendments meet the criteria for a waiver under section 209. For example, EPA 
  must determine if the California enforcement procedures, as amended, are      
  consistent with section 202(a) of the Act.                                    
    Until it has completed its analysis of the waiver request, EPA cannot       
  present a determination that the amended California regulation, and thus      
  California administration and enforcement, do not meet the criteria for a     
  waiver under section 209. Given that section 244 directs EPA to adopt         
  California's procedures unless it makes such a determination, EPA believes    
  that it is required to adopt today California's administration and            
  enforcement procedures. EPA believes this adoption is in accordance with the  
  plain language of section 244. If EPA later determines that the California    
  enforcement procedures do not meet the section 209 waiver criteria, it will   
  propose to amend its regulation regarding enforcement of CFVs according to    
  California procedures.                                                        
    California procedures currently require certification testing of gasoline   
  vehicles either on California reformulated gasoline or on the current federal 
  gasoline test fuel called "indolene." EPA believes that adopting this         
  requirement as a part of adopting California administration and enforcement   
  procedures will allow manufacturers to certify vehicles both for California   
  as well as the other 49 states. In most cases, EPA believes that vehicle      
  designs likely to be certified on California reformulated gasoline to the CFV 
  standards will be capable of being certified to those standards on indolene   
  as well with no technological changes.                                        
    It is possible that some manufacturers may wish to certify vehicles on a    
  gasoline formulation different from either California reformulated gasoline   
  or indolene. For example, a manufacturer may wish to certify and market a CFV 
  engine family for use by fleet operators only in areas where federal          
  reformulated gasoline requirements apply, but where California reformulated   
  gasoline is unavailable or expensive. A CFV engine family certified only on   
  California reformulated gasoline would not be an attractive option to fleet   
  operators in areas covered by federal reformulated gasoline requirements      
  because the vehicles in that family will not have been demonstrated to comply 
  with the CFV standards on federal reformulated gasoline. If certifying that   
  family to the CFV standards on indolene would require additional emission     
  control development effort over the California-fuel version, but certifying   
  on a federal reformulated fuel would not, the manufacturer might prefer to    
  certify on a fuel representative of federal reformulated gasoline. Thus, such 
  a manufacturer might choose to market a line of CFVs which could use the      
  local fuel (reformulated gasoline) instead of only marketing California-fuel  
  versions. In this kind of situation, then, allowing manufacturers the option  
  of certifying to the CFV standards on other gasoline formulations might       
  provide fleets covered by the CFF program with an additional vehicle choice,  
  one which may help them comply in a cost-effective manner with the            
  requirement that they operate their CFVs in covered areas only on fuels on    
  which the vehicles comply with the CFV standards.                             
    While the California procedures adopted here do not appear to permit        
  certification on gasoline different from California reformulated gasoline or  
  indolene, EPA is considering whether it has the authority to propose and      
  promulgate a provision which would permit manufacturers to request            
  certification on a different gasoline formulation. Particularly if interest   
  is shown in such a provision on the part of fleets, vehicle manufacturers,    
  fuel producers, states, or other interested parties, EPA may issue a proposed 
  rule to permit certification on any gasoline formulation.                     
    With respect to the NMOG standard, CAA sections 241(3) and 241(4) provide   
  definitions for NMOG and base gasoline to be used in determining reactivity   
  adjustments for alternative fuels. Section 241(4) further provides that EPA   
  is to modify these definitions and the method used for determining reactivity 
  adjustment factors to conform to the definitions and method used by CARB,     
  provided CARB's definitions are, in the aggregate, at least as protective of  
  public health and welfare as the CAA definitions. CARB's definition of NMOG,  
  contained in the "definitions" section of its LEV program regulations, is     
  identical to the CAA definition. The CAA section 241(4) specifications for    
  "base gasoline" for the most part fall within the specification ranges for    
  CARB's "baseline", i.e., "conventional", gasoline used by CARB in             
  establishing the RAF for methanol-fueled vehicles./18/ Thus, EPA concludes    
  that CARB's regulatory definition of "conventional gasoline" is at least as   
  protective as the CAA definition of base gasoline for determining RAFs.       
    Note /18/ California Exhaust Emission Standards and Test Procedures for     
  1988 and Subsequent Model Passenger Cars, Light-Duty Trucks, and Medium-duty  
  Vehicles, Appendix VIII.                                                      
                                                                                
    To ensure that the administration and enforcement of the CFV exhaust        
  emission standards is undertaken in conformance with section 244, EPA         
  incorporates by reference CARB's test procedures and other regulatory         
  provisions regarding administration and enforcement. (The California          
  Regulatory Requirements Applicable to the Clean Fuel Fleet and California     
  Pilot Programs, April 1, 1994, have been incorporated by reference in 40 CFR  
  88.104-94(k)(2).) Any vehicle certified by CARB in California to the same CFV 
  exhaust emission standards promulgated today will be considered to satisfy    
  the requirements for certification to the federal CFV exhaust standards       
  although the vehicle must meet all other Title II requirements as well as     
  qualify as a CFV. For federal standards which are not currently identical to  
  CARB requirements (e.g., cold CO emissions, evaporative emissions, THC,       
  NMHC), the existing federal administration and enforcement provisions,        
  including the applicable test procedures, will apply.                         
    Provisions established in the Motor Vehicle and Engine Compliance Program   
  Fees rule (57 FR 30044, July 7, 1992) give EPA the authority to recover all   
  reasonable costs associated with enforcement and compliance activities        
  performed by EPA. CFVs certified for use in the Pilot program may be subject  
  to California-only fees if a manufacturer only intends to sell the CFV in     
  California. However, other CFVs certified under the same process may be       
  subject to fees applicable for a federal certificate. This would be the case  
  if such CFVs were sold outside of California (e.g., CFVs used in the CFF      
  program outside California).                                                  
    As EPA proposed in the NPRM, vehicles certified as CFVs are to be labeled   
  according to CARB's revised motor vehicle emission control label              
  specifications./19/ These revised labeling requirements include labeling      
  vehicles to designate that they meet LEV, ULEV or ZEV standards.              
    Note /19/ Contained in California's proposed LEV program, California Code   
  of Regulations, Title 13, section 1965.                                       
                                                                                
  2. Heavy-Duty Clean-Fuel Vehicle Standards                                    
                                                                                
    Today's rule requires that engines intended for use in clean-fuel vehicles  
  greater than 8,500 and up to 26,000 pounds GVWR meet a combined non-methane   
  hydrocarbon (NMHC) plus NOX emissions standard of 3.8 grams per brake         
  horsepower hour (g/Bhp-hr). This new standard applies to all light and medium 
  heavy-duty engines which are to be certified for inclusion in the Clean Fuel  
  Fleet program, independent of fuel type. (Also, this standard applies to      
  heavy heavy-duty engines participating in the Clean Fuel Fleet program for    
  the purpose of generating credits.) Thus, it applies to vehicles operating on 
  gasoline, diesel, alcohols, gaseous fuels, electricity, and other fuels.      
    Section 246(f)(4) of the CAA requires that credit-generating standards be   
  promulgated for heavy-duty clean-fuel vehicles, including standards for       
  heavy-duty ULEVs and ZEVs. The CAA requires these standards to be             
  "comparable", which EPA interprets to mean comparable to the credit-          
  generating standards established for light-duty vehicles.                     
    a. The Heavy-Duty Clean Fuel Vehicle Low-Emission Vehicle NMHC+NOX          
  Standard. Section 245 of the CAA sets forth the statutory framework governing 
  establishment of the heavy-duty clean-fuel vehicle standards. Section 245(a)  
  sets a combined NMHC+NOX standard of 3.15 g/Bhp-hr for engines intended for   
  use in heavy-duty clean-fuel vehicles, reflecting a 50 percent reduction from 
  the current combined HC and NOX standards for heavy-duty diesel engines       
  (HDDE). Section 245(b) permits EPA to set a less stringent standard or        
  standards if EPA determines that the statutory level of 3.15 g/Bhp-hr is      
  infeasible for clean diesel-fueled engines. Under this provision, EPA must    
  make a determination as to the feasibility of this standard for clean diesel- 
  fueled engine technology, taking into account "durability, costs, lead time,  
  safety, and other relevant factors." If the Administrator determines that the 
  standard is not feasible for clean diesel-fueled engines, EPA may set a less  
  stringent standard so long as it is at least a 30 percent reduction from the  
  combined NMHC plus NOX standards for model year 1994 heavy-duty engines. A 30 
  percent reduction would be equivalent to a NMHC plus NOX standard of 4.41 g/  
  Bhp-hr.                                                                       
    EPA determines today that a combined NMHC+NOX emission standard of 3.15 g/  
  Bhp-hr is infeasible for clean diesel-fueled engines, for the reasons         
  discussed below. Under Section 245(b)(1), EPA has the authority to establish  
  a less stringent standard. The only statutory criteria for setting the less   
  stringent standard is the requirement that the standard require at least a 30 
  percent reduction from the combined NMHC+NOX standards for the 1994 model     
  year heavy-duty engines. Because the same standard that will apply to diesel- 
  fueled vehicles will also apply to vehicles run on other fuels (including     
  gasoline), EPA has looked at feasibility for both diesel- and nondiesel-      
  fueled vehicles. Based on these considerations, EPA has decided to set the    
  standard at 3.8 g/Bhp-hr.                                                     
    (i) Establishing the NMHC+NOX Standard. In determining whether the 3.15 g/  
  Bhp-hr NMHC+NOX standard is feasible for clean diesel-fueled heavy-duty       
  engines, EPA believes that the CAA does not require a determination that the  
  standard is feasible for every diesel engine family, but rather that it is    
  feasible for at least enough diesel engine families such that fleet operators 
  have enough choice to meet their requirements under the Clean Fuel Fleet      
  Program. The clean-fuel vehicle standard is not a mandatory national standard 
  for all heavy-duty vehicles manufactured, but instead applies to vehicles     
  that fleet owners in certain areas must buy as a certain percentage of their  
  vehicle purchases beginning in model year 1998.                               
    In the NPRM, EPA proposed a level of 3.5 g/Bhp-hr NMHC+NOX based on         
  concerns about technology, cost, leadtime, and durability for diesel engines  
  as prescribed in section 245 (b) of the CAA. Based on the comments submitted  
  to EPA and further analysis by the Agency, EPA believes that achieving HDDE   
  emission levels below about 3.5 g/Bhp-hr NMHC+NOX would be technically        
  difficult and costly to manufacturers and would not be achievable for an      
  adequate number of light and medium heavy-duty diesel engine families by      
  1998. In their comments, engine manufacturers argued that the 3.15 g/Bhp-hr   
  level, as well as the proposed 3.5 g/Bhp-hr level, would not be               
  technologically and economically feasible for diesel-fueled engines. The      
  Natural Gas Vehicle Coalition (NGVC) argued that the 3.15 g/Bhp-hr level      
  would be feasible for diesel-fueled engines, based largely on a final report  
  by Acurex under contract with CARB, entitled "Technical Feasibility Reducing  
  NOX and Particulate Emissions from Heavy-Duty Engines." /20/ As the analysis  
  summarized below demonstrates, EPA agrees in part with each set of comments,  
  but reaches a conclusion different from both.                                 
    Note /20/ Acurex Environmental Project Under Contract with California Air   
  Resources Board, Final Report, "Technical Feasibility of Reducing NOX and     
  Particulate Emissions From Heavy-Duty Engines," Acurex Environmental Project  
  8450, Contract No. A132-085, April 30, 1993 (found in the docket for this     
  rulemaking).                                                                  
                                                                                
    As a part of its assessment of the potential HDDE emission control          
  technology, EPA studied the Acurex report in depth. Like the Regulatory       
  Support Document associated with this rule,/21/ this report concludes that to 
  achieve a NOX-emission level of 2.5 g/Bhp-hr by 2000 (NOX levels needed to    
  meet a 3.15 g/Bhp-hr NMHC+NOX standard),/22/ diesel-fueled engines would need 
  to be equipped with advanced catalytic trap or EGR (exhaust gas               
  recirculation) technologies. In addition, the 2.5 g/Bhp-hr level would also   
  require the use of a combination of some or all of the following emission     
  control approaches for diesel-fueled engines: very high pressure fuel         
  injection, variable geometry turbocharging, air-to-air aftercooling,          
  optimized combustion, electronic unit injections with minimized sac volumes,  
  optimized fuel injection nozzles, rate shaping, exhaust gas recirculation and 
  sophisticated electronic control of all engine systems. Most of the devices   
  described in the Acurex report are in relatively early stages of development  
  and would require extensive changes in heavy-duty diesel-powered engines      
  compared to today's designs. Acurex projects that achieving this level would  
  be possible, but it would result in a 5 percent fuel economy penalty and a    
  doubling of the engine price of a 1994 diesel-fueled engine. Based on reasons 
  discussed throughout this section, EPA is very doubtful that this standard    
  could be met in a cost-effective manner in time for the production of an      
  adequate number of 1998 model year engine families. However, Acurex has       
  projected that a 3.0 g/Bhp-hr NOX-emission level (approximately equivalent to 
  a 3.5 g/Bhp-hr NMHC+NOX level) is achievable for diesel-fueled engines by     
  1999 with the addition of EGR and oxidation catalyst technology without major 
  new costs or fuel economy penalties.                                          
    Note /21/ U.S. Environmental Protection Agency, Office of Mobile Sources,   
  "Regulatory Support Document: Emissions Standards for Heavy-Duty Fleets,"     
  June 1994 (found in the docket for this rulemaking).                          
    Note /22/ Current certification data indicate that generally all diesel     
  engine families have HC certification levels less than 0.5 g/Bhp-hr, so most  
  reductions would have to be achieved in NOX emissions. Thus, achieving a 3.15 
  g/Bhp-hr NMHC+NOX standard would essentially require NOX-certification levels 
  on the order of 2.5 to 2.7 g/Bhp-hr.                                          
                                                                                
    Also, the NGVC argued that no technological breakthroughs are required to   
  meet the 3.15 standard since each one of these technologies is already in use 
  in one or more commercial diesel engine families to meet the 1994 and 1998    
  standards. They also state that all that would be required to meet the 3.15   
  standard would be the addition of EGR and possibly a particulate trap.        
  Although it is true that some versions of the necessary technologies are in   
  use today, EPA believes, as stated above, that the additional development     
  effort needed to reach very low emission levels would be very costly and      
  would likely limit or eliminate the availability of heavy-duty diesel engines 
  for the program.                                                              
    Furthermore, a review of the 1993 HDE federal certification results         
  clarifies the magnitude of the developmental task for manufacturers to        
  achieve extremely low-emission levels, especially for diesels. The data,      
  which represents engines tested on federal certification fuel, indicates that 
  no current gasoline or diesel HDE family meets or is close to the 3.15 g/Bhp- 
  hr standard on federal certification fuel (for diesel and gasoline engines    
  NMHC and HC are roughly equivalent). Of the 9 gasoline HDE families certified 
  in 1993, three are within one g/Bhp-hr of the standard (see Figure 1). Based  
  on the aftertreatment control technology used by and available for gasoline   
  engines, EPA believes that 3.15 g/Bhp-hr level would be within reach for a    
  number of these families. For diesel engines, however, the 1993 heavy-duty    
  engine federal certification results presented in Figure 1 indicate that      
  achieving the 3.15 g/Bhp-hr standard on federal diesel fuel would be          
  extremely problematic for the majority of engine families by 1998. However,   
  five of the 37 diesel engine families certified in 1993 are within one g/Bhp- 
  hr of the 3.5 g/Bhp-hr NMHC+NOX level (equivalent to NOX-certification level  
  of 3.0 g/Bhp-hr), indicating that a standard in this range would more likely  
  be achieved by a variety of diesel engines on federal certification fuel than 
  would the 3.15 level. Only one of 37 diesel engine families certified in 1993 
  is within one g/Bhp-hr of the 3.15 level; most have combined HC and NOX       
  certification levels of 5.5 g/Bhp-hr or less.                                 
                                                                                
  BILLING CODE 6560-50-P                                                        
                                                                                
              Figure 1: 1993 Heavy-Duty Engine Certification Levels             
                                                                                
                      1993 Gasoline HDE Certification Levels                    
                                                                                
        [INSERT: Bar chart plotting engine families by HC+NOx (g/Bhp-hr)]       
                                                                                
                  1993 Diesel LHDE and MHDE Certification Levels                
                                                                                
        [INSERT: Bar chart plotting engine families by HC+NOx (g/Bhp-hr)]       
                                                                                
  BILLING CODE 6560-50-C                                                        
                                                                                
    There are two existing sets of regulations that will drive heavy-duty       
  engine technology towards low NMHC+NOX levels: the federal 1998 4.0 g/Bhp-hr  
  NOX standard, and the California Air Resources Board (CARB) LEV standard for  
  diesel engines and incomplete medium-duty vehicles of 3.5 g/Bhp-hr NMHC+NOX.  
  EPA received many comments in Docket A-91-28 stating that the 4.0 g/Bhp-hr    
  NOX standard for all 1998 and later HDEs, which is one g/Bhp-hr lower than    
  the existing standard, is feasible for diesel engines. Development of the     
  technology necessary to comply with the 4.0 g/Bhp-hr NOX standard will make   
  it more likely that a significant number of light and medium diesel HDE       
  families will be able to reach emission levels slightly below 4.0 g/Bhp-hr    
  NOX on federal diesel fuel in the future, but it is unlikely that this        
  federal standard will force the development of technologies needed to achieve 
  a 3.15 g/Bhp-hr NMHC+NOX standard on such fuel (i.e., NOX levels of 3.0 g/    
  Bhp-hr or less) since there is no federal requirement to reach lower levels.  
    CARB's 3.5 g/Bhp-hr NMHC+NOx standard is the only other impetus driving     
  technology to achieve emission levels significantly below the 4.0 g/Bhp-hr    
  NOx standard. Engine manufacturers have stated that the CARB 1998 3.5 g/Bhp-  
  hr NMHC+NOx standard for incomplete medium-duty vehicles and diesel engines   
  is feasible, and EPA agrees with CARB's expectation that manufacturers will   
  market a range of LEV diesel HDEs in California which will meet the           
  California standard. However, as with the federal 4.0 g/Bhp-hr NOx standard,  
  it is unlikely the current California standard will prompt the additional     
  technology development needed to reach a 3.15 g/Bhp-hr NMHC+NOx level since   
  there is no requirement to reach levels below 3.5 g/Bhp-hr NMHC+NOx. This is  
  especially true for engines intended for vehicles between 14,000 and 26,000   
  pounds GVWR, which are covered by the Clean Fuel Fleet Program but not the    
  current CARB LEV program.                                                     
    EPA believes it is appropriate to look at the demand that will be created   
  for heavy-duty CFVs as a relevant factor when determining whether a           
  particular combined NMHC+NOx standard for diesel-fueled vehicles is           
  technologically feasible under section 245(b)(1). For the reasons discussed   
  above, EPA believes that achieving a level of 3.15 g/Bhp-hr NMHC+NOx for even 
  a small selection of HDDEs by 1998 will be a very difficult task.             
  Manufacturers will need to invest significantly in research and accelerated   
  technology development, and any engines which reach production would be more  
  costly (in terms of both engine price increase and fuel economy penalty, as   
  discussed above), especially based on the relatively small demand that will   
  be created by the Clean Fuel Fleet Program. In the absence of mandated        
  production, EPA believes that a technological effort of this magnitude is     
  likely to be undertaken by engine manufacturers only under circumstances of a 
  certain, substantial market.                                                  
    The CFF program contains no authority for a production mandate. Thus, the   
  size and certainty of the market is central to whether diesel engines will be 
  developed to meet the requirements of heavy-duty fleets covered by the fleet  
  program. However, only a small number of vehicles will be needed by fleets    
  for their fleet program purchase requirements. For example, during each year  
  of the fleet program EPA estimates that a maximum of only about 2 percent     
  (10,000) of total nationwide new heavy-duty diesel vehicles will be purchased 
  by fleet operators to meet the Clean Fuel Fleet Program requirements./23/     
  This projected market decreases by about 25 percent if California opts out of 
  the Clean Fuel Fleet Program; other potential opt outs by additional states   
  may reduce the market to under one percent of nationwide heavy-duty diesel    
  engine sales (or under about 5000 vehicles). By comparison, based on the      
  implementation schedule of CARB's LEV program, the annual market (30,000) for 
  vehicles required to meet CARB's LEV standard for diesel engines and          
  incomplete medium duty-vehicles of 3.5 g/Bhp-hr NMHC+NOx is approximately     
  three to six times as large as the potential federal clean diesel-fueled      
  market./24/ CARB's program incorporates a phased-in percentage sales mandate  
  for this larger number of vehicles.                                           
    Note /23/ U.S. Environmental Protection Agency, Office of Mobile Sources,   
  "Estimated Number of Fleet Vehicles Affected by the Clean Fuel Fleet          
  Program," Memorandum from Sheri Dunatchik to Docket A-91-25, June 11, 1991.   
    Note /24/ Heavy-duty vehicle population projections for the California LEV  
  program are based on the following: (1) light heavy-duty production reports   
  submitted to the U.S. Environmental Protection Agency for model year 1991 and 
  (2) New Truck Registrations by Manufacturer and State data from the "AAMA     
  Facts and Figures 1993" (page 27) that shows California truck sales to be 10  
  percent of nationwide truck sales.                                            
                                                                                
    EPA is concerned that a market of the size represented by the CFF program   
  will not be seen as sufficient for engine manufacturers to justify the major  
  voluntary technological development efforts necessary to reach a 3.15 g/Bhp-  
  hr standard. Even if some manufacturers do launch such an effort, the likely  
  higher cost and possible fuel economy penalty may make it much more difficult 
  for diesel engine producers to compete for sales with gasoline or alternative 
  fueled engine options which may be available. Since developing and producing  
  vehicles for the fleet program is, by statute, voluntary, the Agency believes 
  that it is very possible that, with a very low emission standard, no diesels  
  will be produced for the clean fuel fleet program. The Act is clear in its    
  intention that EPA may design the fleet program such that clean diesel        
  vehicles can participate. EPA thus concludes that a standard of 3.15 g/Bhp-hr 
  is not feasible for heavy-duty diesel-fueled CFVs taking into account costs,  
  lead time, durability, and other relevant factors, and should not be          
  promulgated at this time.                                                     
    EPA reserves the right to reconsider through rulemaking the 3.15 g/Bhp-hr   
  NMHC+NOx standard at a later time if diesel NOx control technology and the HD 
  clean-fuel engine market develop to a point which would make this level       
  feasible for heavy-duty diesel-fueled CFVs. Such a reconsideration may be     
  prompted by developments in the ongoing CARB HD LEV program now under         
  consideration.                                                                
    ii. NMHC+NOx LEV standard. EPA is adopting an approach for the heavy-duty   
  clean fuel vehicle engine standard that is very similar to the proposed       
  approach. The intent of this approach is to implement a challenging standard  
  in a way that harmonizes as completely as possible the federal standard with  
  CARB's NMHC+NOx LEV standard for diesel engines and incomplete medium-duty    
  vehicles. The Agency believes that the effect of this harmonization is to     
  make the overall national market for clean HDDs significantly larger than it  
  would be with either program alone and will thus assure that clean diesels    
  will in fact be produced by 1998 for the clean fuel fleet program.            
    To meet these objectives, EPA is promulgating a combined NMHC+NOx clean-    
  fuel engine emission standard of 3.8 g/Bhp-hr for heavy-duty engines          
  certified on federal diesel certification fuel. Manufacturers may also        
  certify heavy-duty engines to a standard of 3.5 g/Bhp-hr on California diesel 
  certification fuel, which for a given engine is approximately equal in        
  stringency to the 3.8 g/Bhp-hr standard using federal diesel certification    
  fuel, as described below. The level of stringency represented by these        
  standards should be achievable for at least several diesel engines with       
  fairly straightforward technological improvements and without a serious fuel  
  economy penalty. EPA intends for this approach to assure that the same        
  engines that are developed and produced for the California LEV program will   
  also be acceptable to fulfill the requirements of the Clean Fuel Fleet        
  Program. These vehicles and engines would, as specified by section 242(b) of  
  the Act, also be required to meet all other applicable emission standards and 
  requirements of 40 CFR Part 86 (such as standards for CO, particulates, smoke 
  and evaporative emissions, as applicable).                                    
    As discussed in the NPRM, EPA recognizes that differences between           
  California and federal certification and in-use diesel fuels may cause a      
  difference in emission rates. CARB limits the aromatics content of the test   
  fuel to a maximum of ten percent, while federal test fuel may contain as much 
  as 35 percent aromatics. There is evidence to suggest that the use of federal 
  test fuel can result in higher NMHC+NOX emissions than the use of CARB fuel   
  in the same engine. Apparently, this occurs because the higher aromatic       
  content of the fuel reduces its cetane rating and thus combustion is slightly 
  less enhanced. Data reported in the NPRM for a 1991 prototype DDC Series 60   
  heavy heavy-duty engine showed this difference to be in the range of 0.3 g/   
  Bhp-hr offset./25/                                                            
    Note /25/ "Effects of Fuel Aromatics, Cetane Number, and Cetane Improver on 
  Emissions from a 1991 Prototype Heavy-Duty Diesel Engine," T. Ullman, R.      
  Mason, and D. Montalvo, Southwest Research Institute, SAE Paper 902171., U.S. 
  Environmental Protection Agency, Office of Mobile Sources, "Effect of Test    
  Fuel Differences on NMHC+NOX Emissions," Memorandum from Michael Samulski to  
  the docket of this rulemaking, February 23, 1993.                             
                                                                                
    In addition to the analysis of the 1991 prototype heavy-duty diesel engine  
  referenced in the NPRM, EPA has used a similar analysis to examine diesel     
  fuel effects based on data presented in a study performed on a 1993 prototype 
  Navistar Diesel DTA 466 medium heavy-duty engine./26/ As had been done in the 
  earlier analysis, EPA compared federal and California diesel fuels on the     
  basis of aromatic percent and cetane number. EPA used the specified aromatic  
  levels of 10 percent for California test fuel and 35 percent for federal test 
  fuel and natural cetane numbers of 50 and 46 for typical California and       
  federal certification fuels, respectively./27/ An API gravity number typical  
  of both test fuels of 36 degrees was used. The following regression equations 
  were developed in the study conducted on the 1993 engine for total            
  hydrocarbon (THC) and NOX:                                                    
    Note /26/ Diesel Fuel Property Effects on Exhaust Emissions from a Heavy    
  Duty Diesel Engine that Meets the 1994 Emissions Requirements, "C. McCarthy,  
  Amoco Oil Co., W. Slodowske, E. Sienicke, and R. Jass, Navistar International 
  Transportation Corp., SAE Paper 922267.                                       
    Note /27/ The cetane numbers used in the EPA analysis on the 1993 heavy-    
  duty engine were based on the following: (1) "Development of the First CARB   
  certified California Alternative Diesel Fuel", M. Nikanjam, SAE Paper 930728, 
  (2) Section 2282, Title 13, California Code of Regulations procedure for      
  certifying diesel fuel formulations resulting in equivalent emissions         
  reductions and (3) Cummins Engine Company and Caterpiller diesel fuel         
  formulations for federal diesel fuel. These cetane numbers are natural cetane 
  numbers (without cetane improver).                                            
                                                                                
  THC [g/Bhp-hr] = 0.819 - 0.01942 * (Natural Cetane) + 0.01159 * (API)         
  NOX [g/Bhp-hr] = 6.593 + 0.01183 * (SFC Aromatics %) - 0.02497 * (Natural     
      Cetane) - 0.02365 (API)                                                   
                                                                                
    Substituting the values selected above for percent aromatics and cetane     
  numbers into these equations, the Agency calculated a THC + NOX offset of     
  about 9.7 percent. Applying this percent offset to the 3.5 g/Bhp-hr standard  
  for CARB diesel fuel, the Agency analysis calculated that the offset would be 
  about 0.34 g/Bhp-hr THC + NOX. (This analysis assumed that the offset would   
  apply equally whether THC or NMHC was being considered; the Agency has no     
  data to indicate that the small methane emissions component in diesel         
  emissions would affect the relative behavior of the engine on the two fuels). 
    Thus, the Agency concludes that diesel engines certified to a 3.5 g/Bhp-hr  
  level on California diesel fuel would for typical engines, result in          
  emissions of approximately 3.8 g/Bhp-hr for the same engines operated on      
  federal diesel fuel, confirming the estimate made in the NPRM. In their       
  comments engine manufacturers quoted the same data that EPA has used for the  
  1991 and 1993 prototype diesel engines, but used different assumptions for    
  the cetane number for in-use diesel fuel. Also, the industry analysis did not 
  adjust the offset proportionally to account for the much lower emissions of   
  CFVs as compared to the current engine which generated the test data. In      
  their comments, they concluded that the offset between federal certification  
  fuel and California certification fuel may be more in the range of 0.55-0.66  
  g/Bhp-hr. EPA has examined the assumptions used in the industry analysis and  
  concluded that the EPA analysis is a more appropriate approach for            
  determining the expected emissions offset. While this conclusion is based on  
  data from a single engine, the 1993 engine is of the appropriate size (medium 
  heavy-duty) from which to draw a conclusion for this program and the study    
  was done on a meaningful array of diesel test fuels. It is likely that if     
  similar data were collected on other engines, somewhat different values for   
  the CARB/federal fuel offset might be observed. Until such a time when        
  additional data becomes available, EPA will assume that offsets for other     
  heavy-duty diesel engines would range on either side of the 0.34 g/bhp-hr     
  level EPA has developed for the 1993 engine. Thus, the Agency believes that   
  its analysis reasonably accounts for potential fuel variability and that the  
  0.34 g/Bhp-hr value represents a reasonable estimate for the average          
  emissions offset between federal certification fuel and California            
  certification fuel. If a reduction catalyst is used as a means to reduce NOX  
  levels, concerns over fuel variability diminish significantly. The CARB/      
  federal fuel offset would tend to be less because the reduction catalyst      
  would reduce emissions proportionally for both fuels. While the use of        
  reduction catalysts may not be universal, EPA expects that some light/medium  
  heavy-duty engine families will use reduction catalyst technology to meet the 
  NOX target level. Additional data and analysis supporting the above           
  conclusion of the offset between federal and California diesel fuel can be    
  found in the Summary and Analysis of Comments document for this rulemaking.   
    Based on its analysis of the emissions offset above, EPA has set the        
  emission standard for HDD CFVs certified on federal diesel fuel at 3.8 g/Bhp- 
  hr NMHC + NOX. This standard is consistent with EPA's intent that the heavy-  
  duty clean-fuel vehicle standards be of as close to equivalent stringency as  
  possible to the CARB LEV standard for similar vehicles to assure the          
  production of an adequate number of diesel engine models for the clean fuel   
  fleet program. Further, because the Agency is reasonably confident that in-   
  use emissions of a engine certified at 3.5 g/Bhp-hr on California fuel will   
  emit in the range of 3.8 g/Bhp-hr on federal fuel, EPA will grant a federal   
  certificate of conformity to a manufacturer which demonstrates compliance     
  with the 3.5 g/Bhp-hr standard on California certification fuel. While it is  
  possible that individual engines certified on California fuel may experience  
  a slightly different offset when operated on federal diesel fuel (e.g., when  
  a cetane number is much different between the fuels), EPA believes that this  
  will be the exception and that in-use performance on federal diesel fuel will 
  average about 3.8 g/Bhp-hr. The use of federal fuel in engines certified on   
  California fuel is consistent in this case with the fuel use provisions of    
  sections 246(b) and 241(2), since EPA has concluded that such engines indeed  
  comply with the clean fuel vehicle requirements on federal diesel fuel.       
    As another way of harmonizing the CARB LEV program and the CFF program to   
  ensure a sufficient number of HDDEs will be available by 1998 for the fleet   
  program, EPA will only test engine families which were certified to CFV       
  standards on California diesel fuel on diesel fuel meeting California         
  specifications during any Selective Enforcement Audit (SEA) testing or in-use 
  recall enforcement testing. The Agency believes that if manufacturers of HD   
  CFVs certified on California fuel perceive that their engines may be subject  
  to later EPA testing on federal diesel fuel, then they may desire to perform  
  additional testing of these engines on federal certification diesel fuel for  
  the purpose of assuring themselves of in-use compliance on federal diesel     
  fuel. This approach to SEA and in-use recall testing should assure            
  manufacturers that they will not need to perform any additional testing at    
  certification beyond that required for California certification. Fuel meeting 
  California diesel test fuel specifications is an acceptable test fuel under   
  the FTP because it meets the federal fuel specifications. This policy of the  
  Agency using fuel meeting California diesel test fuel specifications for SEA  
  and recall testing applies only to CFVs. If the Agency becomes aware of       
  changed circumstances which indicate that this policy is inappropriate, the   
  Agency reserves the right to discontinue this policy.                         
    For gasoline-fueled HD CFVs, EPA is aware of no evidence to suggest any     
  significant difference in emissions between such vehicles operating on        
  federal and California certification gasolines; thus the technical basis for  
  separate standards which exists for diesels does not apply for gasoline       
  engines. Commenters did not respond to the issue of the appropriateness of a  
  single standard for all HDEs. However, EPA believes that in general, a single 
  standard for all fuels provides equity among manufacturers of different types 
  of engines for this program. Also, section 245 of the Act seems to indicate   
  that Congress intended for there to be a single heavy-duty CFV standard.      
  Therefore, as for diesel engines, EPA today also promulgates a standard of    
  3.8 g/Bhp-hr for gasoline clean-fuel vehicle engines certified on federal     
  gasoline test fuel. As with diesel engines, gasoline engines demonstrating    
  compliance with the California 3.5 g/Bhp-hr standard on California gasoline   
  certification fuel will be eligible for a federal certificate.                
    Given the arguments above, as well as the fact that manufacturers have more 
  than three years before the purchase requirements for clean-fuel fleet        
  vehicles begin, EPA believes that several heavy-duty diesel engine families   
  will achieve a standard of 3.8 g/Bhp-hr NMHC + NOX on federal certification   
  fuel or 3.5 g/Bhp-hr NMHC + NOX on California certification fuel by the 1998  
  model year. Also, EPA believes that most gasoline-fueled HDE families can     
  meet a standard of either 3.8 g/Bhp-hr on federal certification fuel or 3.5   
  g/Bhp-hr on California fuel by the 1998 model year. These clean fuel vehicle  
  standards will apply to HDEs used in clean-fuel fleet vehicles of 8,501 to    
  26,000 lbs. GVWR to meet the purchase requirements of the fleet program.      
    b. Heavy-Duty ULEV and ZEV Standards. As previously discussed, section      
  246(f)(4) of the CAA requires EPA to promulgate emission standards for ULEVs  
  and ZEVs, for the purpose of determining fleet program credits. The provision 
  states that the standards:                                                    
                                                                                
  * * * shall be more stringent than those otherwise applicable to clean-fuel   
  vehicles under this part* * * . The standards* * *for [light-duty] vehicles*  
  * *shall conform as closely as possible to standards which are established by 
  the State of California for ULEV and ZEV vehicles in the same class. For      
  vehicles of 8,500 lbs. GVWR or more, the Administrator shall promulgate       
  comparable standards for purposes of this subsection.                         
                                                                                
    EPA interprets this comparability criteria to mean that ULEV and ZEV        
  standards for heavy-duty engines should require approximately the same        
  percentage of emission reduction compared to heavy-duty CFV LEV standards as  
  light-duty CFV ULEV and ZEV standards require compared to light-duty CFV LEV  
  standards. Under this provision, EPA must determine the appropriate level for 
  the heavy-duty ULEV and ZEV standards. EPA proposed this interpretation and   
  did not receive any comments objecting to it.                                 
    EPA also believes it is appropriate to take California's ULEV and ZEV       
  standards into consideration and attempt to harmonize the federal and         
  California standards where possible. As mentioned above in the section        
  pertaining to the feasibility of the HD CFV LEV standard, EPA believes such   
  harmonization is valuable because it helps create a single larger market for  
  heavy-duty ULEVs and ZEVs rather than two smaller markets. A single larger    
  market makes it more economical for manufacturers to produce heavy-duty ULEVS 
  and ZEVs, which makes it more likely that manufacturers will choose to        
  produce vehicles that can participate in the federal program. (The federal    
  program does not have a sales mandate for manufacturers, so their             
  participation is voluntary and controlled, in part, by market demand for      
  their products.)                                                              
    EPA also believes it has authority to consider harmonization of federal     
  heavy-duty ULEV and ZEV standards and California incomplete medium-duty       
  vehicle and diesel engine ULEV and ZEV standards in setting the federal       
  standards./28/ As explained above, EPA interprets "comparable standards" to   
  mean that heavy-duty CFV ULEV and ZEV standards must be comparable to light-  
  duty CFV ULEV and ZEV standards. Since the Act requires EPA to establish      
  federal light-duty ULEV and ZEV standards that conform as closely as possible 
  to California's light-duty ULEV and ZEV standards, harmonization of the       
  federal heavy-duty ULEV and ZEV standards and California incomplete medium-   
  duty vehicle and diesel engine ULEV and ZEV standards could be part of the    
  comparability determination. In addition, the direction of section 246(h) to  
  set "comparable standards" gives EPA some discretion in establishing          
  standards. EPA believes it is appropriate to consider California's standards  
  in exercising this discretion. EPA believes that, since the federal HD ULEV   
  and ZEV standards are voluntary credit-generating standards, their intended   
  purpose is primarily to provide compliance flexibility for manufacturers and  
  fleet operators. The Agency's goal then, in selecting these standards, is to  
  provide the maximum flexibility allowable under section 246(f)(4) of the Act, 
  while ensuring that there will be no negative impacts on the environment.     
    Note /28/ Beginning with the 1995 model year, CARB's medium-duty vehicles   
  include vehicles with a GVWR of 14,000 pounds or less.                        
                                                                                
    i. Ultra low-emission vehicle standards. EPA is adopting standards for      
  heavy-duty ULEVs NMHC+NOX, CO, particulate, and formaldehyde emissions as     
  specified below in Table 5. These standards are the same as those that were   
  proposed, except the formaldehyde standard, which is lower than originally    
  proposed. In the opening statement at the public hearing for the proposal and 
  in a memorandum that was placed in the docket and distributed at the public   
  hearing,/29/ EPA informed the public that the proposed standard for           
  formaldehyde was a typographical error and requested comment on the change of 
  the heavy-duty ULEV standard to the level specified in Table 5. EPA did not   
  receive any comments objecting to this level for the formaldehyde ULEV        
  standard. The final heavy-duty ULEV standards require reductions in emissions 
  that are comparable to the respective emission reductions required of light-  
  duty ULEVs, and are consistent with the respective requirements of the        
  California LEV program.                                                       
    Note /29/ U.S. Environmental Protection Agency, Office of Mobile Sources,   
  "Request for Comment on Revised Formaldehyde Standard for Heavy-Duty ULEVs    
  for the Clean Fuel Fleet NPRM," July 12, 1993, Memorandum from Bryan J.       
  Manning through Tad Wysor to docket A-92-30 (Document Number III-A-03).       
                                                                                
    As proposed, EPA is setting a combined NMHC + NOX HD CFV ULEV standard that 
  is approximately a 30 percent reduction from the HD CFV LEV standard. The     
  comparable light-duty CFV ULEV standards require reductions from light-duty   
  CFV LEV standards of 38 to 50 percent of NMOG emissions and 45 to 50 percent  
  for NOX emissions. Even though EPA has separate NMOG and NOX standards for    
  light-duty CFV ULEVs, the Agency does not believe it is required to establish 
  such separate standards for heavy-duty CFV ULEVs. Rather, EPA believes it is  
  appropriate to have a combined NMHC + NOX heavy-duty CFV ULEV standard        
  because heavy-duty CFV LEV standards have a combined NMHC + NOX standard      
  rather than separate NMOG and NOX standards (as do light-duty CFV LEVs and    
  ULEVs). Furthermore, a combined NMHC + NOX standard is consistent with the    
  California incomplete medium-duty vehicle and diesel engine ULEV standard.    
  EPA proposed this interpretation and did not receive any comments objecting   
  to a combined NMHC + NOX standard for HDEs.                                   
    EPA also is setting specific emission standards for CO and particulates     
  that require a reduction in emissions from the heavy-duty CFV LEV standards   
  of 50 to 54 percent and 50 percent, respectively, as proposed. (For both CO   
  and particulates, heavy-duty CFV LEVs must meet the same standards as do      
  conventional heavy-duty vehicles. Thus, for these standards, the reductions   
  in emissions for heavy-duty CFV ULEV standards are the same whether they are  
  compared to conventional or CFV LEV heavy-duty standards.) The comparable     
  light-duty CFV ULEV standards require reductions in CO and particulate        
  emissions of 50 percent each fr