Vehicle Conversions

Photo of an engine converted to run on compressed natural gas.

What kinds of conversions are available?

An aftermarket conversion is a vehicle or engine modified to operate using a different fuel or power source. Conventional vehicles and engines from original equipment manufacturers (OEMs) can be converted to run on fuels like propane, natural gas, or electricity.

Many OEMs offer alternative fuel and advanced technology vehicles, and models, fuels, and technologies vary. These vehicles are considered conversions when gasoline engines are modified to run on alternative fuels. Similarly, vehicles that are already in use can also be converted. Models, fuels, and technologies vary.

The National Renewable Energy Laboratory produced What Fleets Need to Know About Alternative Fuel Vehicle Conversions, Retrofits, and Repowers. The report discusses important considerations, "pro tips," and best practices for converting vehicles to run on alternative fuels such as natural gas and propane.

All vehicle and engine conversions must meet emissions and safety standards instituted by the U.S. Environmental Protection Agency, the National Highway Traffic Safety Administration, and state agencies like the California Air Resources Board.

Conversion Basics 

Learn about the basics of engine and vehicle conversions and installation.

Conversion Regulations 

Learn about the emissions and safety regulations that apply to conversions.