Law & Order

EPA Streamlines Process for Approving Vehicle Fuel Conversions

The U.S. Environmental Protection Agency (EPA) has streamlined the process for approving fuel conversion systems. The conversion systems allow light- and heavy-duty vehicles to run on alternative fuels (natural gas, propane, alcohol, electricity, etc.) while complying with Clean Air Act emissions standards. The EPA has established a three-tiered compliance process based on the age of the vehicle.

Under the old one-size-fits-all approach, the vehicle and engine conversion system must be covered by a certificate of conformity demonstrating emissions compliance. Under the new system, a certificate is only required for newer vehicles (less than two years old). Conversion system manufacturers need to perform certification tests to demonstrate the vehicle complies with exhaust and evaporative emissions standards as well as with on-board diagnostic requirements, but manufacturers may then apply a single set of test data to more vehicle and engine conversions than is currently allowed. 

To certify alternative-fuel conversions for intermediate-aged engines (more than two years old but still within their useful life), manufacturers need to perform exhaust and evaporative emissions tests to demonstrate compliance with EPA standards and then forward that test data to the EPA with a statement that the OBD system will continue to operate properly after the conversion. For vehicles that have outlived their useful life, the EPA conversion manufacturers must submit a detailed description of the conversion technology to demonstrate that it is well engineered and should work. Manufacturers must also submit an OBD diagnostic scan tool report to show that the OBD system continues to operate properly. 

For more information, contact Stuart Gosswein at