Flexible fuel vehicles (FFVs) are designed to run on gasoline or a blend of up to 85% ethanol (E85). Except for a few engine and fuel system modifications, they are identical to gasoline-only models. FFVs experience no loss in performance when operating on E85. However, since ethanol contains less energy per volume than gasoline, FFVs typically get about 25-30% fewer miles per gallon when fueled with E85.1
FFVs have been produced since the 1980s, and dozens of models are currently available. Since FFVs look just like gasoline-only models, you may be driving an FFV and not even know it.
Do You Have a Flex-Fuel Vehicle?
Look for the Yellow Gas Cap
Most manufacturers started putting yellow gas caps on FFVs as of model year 2008 (2006 for General Motors).
Check the Fuel Door
Some FFVs have labels on the fuel door indicating fuel type.
Check Your Owner's Manual
It usually specifies which fuels can be used in your vehicle. If you don't have a manual, the manufacturer's website may have an electronic version.
Look for Badges on Your Vehicle's Body
Badges with terms such as "E85," "Flex-Fuel," or "FFV" may indicate that your vehicle can use E85.
Stations that Sell E85 (Alternative Fuels and Advanced Vehicles Data Center [AFDC])
Flexible Fuel Vehicle (FFV) Cost Calculator (compare costs for operating your vehicle on gasoline and E85)
- West, Brian H., Alberto J. Lopez, Timothy J. Theiss, Ronald L. Graves, John M. Storey, and Samuel A. Lewis. 2007. Fuel Economy and Emissions of the Ethanol-Optimized Saab 9-5 Biopower. SAE Technical Paper 2007-01-3994.