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 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 This website is no longer updated and links to external websites and some internal pages may not work.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 »

Vehicle and Engine Certification

Templates for Heavy Duty System Conversion for Alternative Fuels

Use the following templates for intermediate age and outside useful life system conversions for alternative fuel.

Free Viewers