Flexible Fuel Vehicles

Flexible fuel vehicles (FFVs) have an internal combustion engine and are capable of operating on gasoline and any blend of gasoline and ethanol up to E85 (or flex fuel). E85 is a gasoline-ethanol blend containing 51% to 83% ethanol, depending on geography and season. According to Polk, there are more than 17.4 million FFVs on U.S. roads today. However, many flexible 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 perceivable difference is that the fuel economy is lower when FFVs run on blends above E10, due to the lower energy content in ethanol compared to gasoline.

For fleets that have to comply with federal acquisition regulations, flexible fuel vehicles are considered 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.