Under the Clean Air Act all fuel additives must be registered with EPA. EPA also has a program which tests aftermarket devices and certain fuel additives. EPA, however, does not certify, approve, or endorse any of these products. In fact, EPA testing has not found that any of them significantly benefit fuel economy or reduce exhaust emissions.
For more information:
- Frequent Questions for EPA's Office of Transportation and Air Quality
- Devices and Additives to Improve Fuel Economy and Reduce Pollution - Do They Really Work? (5 pp, 115 KB, About PDF)
- Federal Trade Commission: "Gas-Saving" Products
For more information about gasoline standards and registered gasoline additives:
For further questions, you may contact the EPA Fuels Program: