Alternative Fuel Conversion
Search for Documents
Search the Document Index System (DIS) database to find
- Advisory Circular
- Applications for Certification
- Certificates of Conformity
- Certificates of Summary
- Manufacturer Guidance Letters
- Verify System Documentation
This web site provides links to information about alternative fuel conversions, which are vehicles that are modified to run on a different fuel than the one for which they were designed. Most conversions involve switching gasoline or diesel vehicles to operate instead on a gaseous fuel such as natural gas or propane, an alcohol fuel, or electricity.
Any change to a vehicle's original certified configuration, including conversion, is a potential violation of the Clean Air Act prohibition against tampering (PDF) (33 p, 1.4M, January 2009). To avoid a tampering charge, converters must follow EPA protocol. Please see Certification Procedures and Guidance Letters for detailed information about these requirements.
EPA is evaluating its alternative fuels conversions policy and may consider updating certain requirements. Any new or updated information will be available here. If you would like to receive an email when information on this site is updated, register your email address with Enviroflash by going to https://enviroflash.epa.gov/enviroflashOTAQPublic/Subscriber.do?method=start and signing up for "Alternative Fuel Vehicle Conversions."
For further information or assistance regarding this Web page, please contact the Compliance Information Hotline at (734) 214-4343 or email: complianceinfo@epa.gov.
On this page you will find:
- Certification Procedures & Guidance Letters
- Fact Sheets on Alternative Fuels
- Other EPA Links
- External Links
NOTE: You will need Adobe Acrobat Reader, available as a free download, to view some of the files on this page. See EPA's PDF page to learn more about PDF, and for a link to the free Acrobat Reader.
Certification Procedures and Guidance Letters
- Updated Certification Guidance for Alternative Fuel Converters (PDF) (22 pp, 150K, CISD-06-02[LD-AFC], February 3, 2006)
- OBD II Systems on Aftermarket Alternative Fuel Conversions (PDF) (4pp, 101K, September 2005)
- Alternative Fuel Converters Contact List (PDF) (1 pp, 55K, November 2008)
- Compliance Fees
- Engine Certification (Nonroad and Heavy-Duty Highway)
- Light-Duty Vehicle and Engine Emission Certification
- Verify: Engine and Vehicle Compliance System
Fact Sheets on Alternative Fuels
- Electric Vehicles (also available as a PDF file, 2 pp, 68K, EPA420-F-00-034, March 2002)
- Biodiesel (also available as a PDF file, 1 pp, 70K, EPA420-F-06-044, October 2006)
- Fuel Cells - EPA's Web page providing general information on fuel cells.
- E85 and Flex Fuel Vehicles (also available as a PDF file, 1 pp, 70K. EPA420-F-06-047, October 2006)
Other EPA Links
- Presentation: EPA Alternative Fuel Conversion Policies (PDF) (12 pp, 51K, April 19, 2009)
- Fact Sheet: Devices and Additives to Improve Fuel Economy and Reduce Pollution - Do They Really Work? | PDF Version ( 5 pp, 770K, EPA420-F-09-013, March 2009 )
- Green Vehicle Guide - Information about environmental performance of vehicles.
- Reformulated Gasoline
- SmartWay Grow & Go - EPA developed this program to promote the environmental benefits of renewable fuels, and provide a renewable fuel component for EPA's existing SmartWay Transport Partnership. This program will help reduce U.S. dependence on petroleum, and improve our environment by reducing emissions of harmful pollutants and greenhouse gases.
External Links
- Alternative Fuels and Fleet Efficiency, U.S. Department of Agriculture
- Alternative Fuels Data Center, U.S. Department of Energy - This website provides information on alternative fuels, alternative fuel vehicles, fleets, resources, etc.
- Alternative Fuel Refueling Station Locator, U.S. Department of Energy
- Alternative Fuel Vehicles & High Efficiency Vehicles (Calif Energy Commission) - Demonstration and incentive programs
- Clean Cities Information, U.S. Department of Energy - Public/private partnerships that deploy AFVs, and build infrastructure
- Energy Information Administration, U.S. Department of Energy Provides estimated consumption of alternative fuels, number of alternative fuel vehicles in use, survey data, articles, etc.
- Federal Trade Commission (FTC) - Alternative Fuels & Vehicles (labeling requirements, etc.)
- Green Guide to Cars and Trucks American Council for an Energy-Efficient Economy (ACEEE)