An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to www.epa.gov. This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Emission Standards Reference Guide for On-road and Nonroad Vehicles and Engines

Emission Standards Reference Guide for On-road and Nonroad Vehicles and Engines

This guide contains tables listing federal emission standards for on-road and nonroad vehicles and engines, and related fuel sulfur standards. Each table includes the standards, useful life, warranty period, and the availability of averaging, banking, and trading (ABT). This guide is for reference purposes only; it does not include detailed information about all variations and restrictions associated with the standards. Refer to each table to find the applicable Code of Federal Regulations (CFR) citations which provide complete information on the standards.