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Flex-Fuel Vehicles

Flex-fuel truck

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).

Yellow flex-fuel gas cap

Check the Fuel Door

Some FFVs have labels on the fuel door indicating fuel type.

Flex-fuel label on fuel door

Look for Badges on Your Vehicle's Body

Flex-fuel badge Flex-fuel badge Flex-fuel badge

Check Your Owners Manual

Check the Vehicle Identification Number (VIN)

The following Web sites provide information on identifying flex-fuel vehicles using the VIN and other methods:

More Information

Fuel Economy Information for Flexible Fueled Vehicles

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)

MotorWeek Videos

MotorWeek segments provided by Maryland Public Television

Flex Fuel Vehicle Videos
Data Sources

1. 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.