Flexible Fuel Vehicles

Flexible fuel vehicles (FFVs) have an internal combustion engine and are capable of operating on gasoline, E85 (a gasoline-ethanol blend containing 51% to 83% ethanol, depending on geography and season), or a mixture of the two. According to the U.S. Energy Information Administration, there are more than 8 million FFVs on U.S. roads today. However, many flex fuel vehicle owners don't realize their car is an FFV and that they have a choice of fuels.

Other than employing an ethanol-compatible fuel system and powertrain calibration, FFVs are similar to their conventional gasoline counterparts. The only difference is that the fuel economy is lower when FFVs run on ethanol. Their power, acceleration, payload, and cruise speed are comparable whether running on ethanol or gasoline.

Flexible fuel vehicles qualify as alternative fuel vehicles (AFVs) under the Energy Policy Act of 1992.

How Flex Fuel Vehicles Work

FFVs have one fueling system, which is made up of ethanol-compatible components and a powertrain controller calibrated to accommodate the higher oxygen content of E85. View the illustration at the right to learn about the special features of an FFV.