We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Vehicle and Engine Certification

Evaluation Program for Aftermarket Retrofit Devices

IMPORTANT REMINDER

EPA does not approve, certify, endorse, or register any products that pass through this voluntary evaluation program. Neither does EPA approve, certify, endorse, or register any independent laboratory or the test results from any independent laboratory. Any claims by a manufacturer to the contrary are false.

EPA conducts a voluntary program to evaluate aftermarket devices and fuel additives that manufacturers claim will improve fuel economy and/or reduce exhaust emissions for passenger cars and trucks. The purpose of the Aftermarket Retrofit Device Evaluation Program (also known as the "511 Program") is to generate, analyze, and disseminate technical data on the effectiveness of such products.

Materials for Consumers

Consumers who are interested in learning more about these devices should review the following documents:

Materials for Manufacturers

Manufacturers who are interested in learning more about this program or having a device evaluated should review the following documents:

Test Reports

These test reports are for all of the specific products tested by EPA under the Aftermarket Retrofit Device Evaluation Program.