Transportation and Air Quality
- What is the federally mandated warranty for emission controls on my car?
- Why is there ethanol in gasoline?
- Does the fuel used in fuel economy testing contain ethanol?
What's New in OTAQ
OTAQ Recent Additions
- April 17: Seven top performing SmartWay affiliates were recognized by EPA as 2015 SmartWay Affiliate Challenge Honorees.
- March 26: EPA releases the 2013 model year light-duty GHG performance report for automakers.
- March 2: New fun, interactive content added to our Green Vehicle Guide. Learn about hydrogen FCVs, alternative fuels, and why your mileage may vary.
OTAQ Press Releases
- April 21, 2015: EPA Awards $1.3 Million Clean Diesel Grant to the Port of Los Angeles
- April 21, 2015: EPA Awards $5 million in Clean Diesel Grants to Protect Health of Communities near Ports
- March 26, 2015: EPA Report: Automakers Surpassing Light-Duty Greenhouse Gas Standards
OTAQ Federal Register Notices
- April 24, 2015: Notice of Opportunity To Comment on an Analysis of the Greenhouse Gas Emissions Attributable to Production and Transport of Brassica Carinata Oil for Use in Biofuel Production
- April 22, 2015: Control of Emissions From Nonroad Spark-Ignition Engines at or Below 19 Kilowatts
- April 21, 2015: CFR Correction: Sulfur Dioxide Allowance System
EPA's Office of Transportation and Air Quality protects public health and the environment by regulating air pollution from motor vehicles, engines, and the fuels used to operate them, and by encouraging travel choices that minimize emissions. These "mobile sources" include cars and light trucks, heavy trucks and buses, nonroad engines, equipment, and vehicles. For more information see:
- About the Office of Transportation and Air Quality (OTAQ)
- About the National Vehicle and Fuel Emissions Laboratory (NVFEL)
OTAQ's top sites
OTAQ's programs and website topics (A detailed list of programs and topics is on our site map.)
Overview:Pollutants & Programs
Information on how much air pollution, air toxics, and greenhouse gases are emitted by mobile sources, the programs OTAQ has undertaken to control these emissions, and the impact of those programs on air quality and climate change.
On-Road Vehicles & Engines
Information about fuel economy, emission standards and regulations, emission recall, certification and compliance, inspection and maintenance, diesel retrofit, evaluating the benefits of inventions designed to reduce emissions, and importing vehicles and engines.
Nonroad Engines, Equipment
Information about nonroad engines, equipment and vehicles: emission standards and regulations, certification and compliance, and diesel retrofit programs.
- Diesel Boats & Ships
- Gasoline Boats & Personal Watercraft
- Nonroad Diesel Equipment
- Forklifts, Generators & Compressors
- Lawn & Garden
- Snowmobiles, Dirt Bikes, & ATVs
Fuels & Fuel Additives
State & Local Transportation
Modeling, Testing, & Research
Information on modeling and inventories for estimating emissions from highway vehicles, nonroad sources, and fuels; testing and measuring emissions; research into clean automotive technologies; and emission factors research.