Vehicle Conversion Basics

Photo of a vehicle.

A Ford Transit Connect converted to run on compressed natural gas.

A converted vehicle or engine is one modified to use a different fuel or power source than the one for which it was originally designed. This includes converting a gasoline-powered vehicle to run on propane or natural gas.

Dedicated, Bi-Fuel, and Dual-Fuel Conversions

Vehicles and engines can be converted to "dedicated" configurations, where they operate exclusively on one alternative fuel. They can also be converted to "bi-fuel" configurations that have two separate tanks and fuel systems—one for conventional fuel and another for an alternative fuel. In this case, either fuel can be accessed by flipping a switch. Although EPA regulations refer to bi-fuel configurations as “dual-fuel,” this term typically refers to a third type of configuration where two fuels are used together. An example is a heavy-duty natural gas vehicle that uses a small amount of diesel fuel for ignition assistance.

Conversion Systems Installation

When you purchase a light-duty alternative fuel vehicle through a dealership, the conversion system is installed by the system manufacturer or by a qualified system retrofitter (QSR) who has met strict requirements in order to convert OEM vehicles. When converting an in-service vehicle, the work should always be completed by a technician associated with a QSR, also referred to as an upfitter or installer, who is associated with a manufacturer and holds all relevant emissions-related certifications, tampering exemptions, and permissions. Ford's Qualified Vehicle Modifier program is an example of this.

Converting, retrofitting, or repowering a vehicle can result in long-term return on investment while helping fleet managers achieve sustainability goals. To learn about technology options and considerations for fleets pursuing a vehicle conversion, as well as best practices for selecting and working with project partners, service providers, and reputable vendors, see the report What Fleets Need to Know About Alternative Fuel Vehicle Conversions, Retrofits, and Repowers.