Fuels and Fuel Additives
Tier 2 Gasoline Sulfur Program
Tier 2
- The Tier 2 program regulations are located in 40 CFR 80 subpart H.
- Please visit the Tier 2 reporting page for compliance forms and instructions for this regulation.
- For the most updated fuel regulations, please visit the Electronic Code of Federal Regulations (e-CFR).
Sulfur is a natural component in crude oil that ends up in gasoline and diesel unless removed. Sulfur in gasoline impairs the effectiveness of emission control systems and contributes to air pollution. By removing most sulfur from gasoline, new advanced emission controls will work longer and more efficiently, and air pollution will be reduced.
The Tier 2 Gasoline Sulfur program reduces the sulfur content of gasoline by up to 90 percent, enabling the use of new emission control technologies in cars and trucks that reduce harmful air pollution. The Tier 2 program marked the first time EPA treated vehicles and fuels as a system. The program grew out of a Clean Air Act requirement that EPA consider the need, feasibility, and cost-effectiveness of stronger tailpipe emission standards beginning in 2004. Requirements for use of low-sulfur gasoline enabled use of advanced emission control systems in cars, pickups, SUVs, and vans beginning in model year 2004. Vehicles meeting Tier 2 emission standards are 77 to 95 percent cleaner than earlier models.
If you have questions or request information, please contact the appropriate support or help line found on the Support & Help page.
Please visit EPA's Transportation and Air Quality web-based repository of mobile source documents, Document Index System (DIS). This searchable repository contains regulations, Federal Register notices, policy letters, and guidance documents.
Please visit our Related Links page for other fuel related information within EPA, other U.S. Agencies, and other fuel related websites.