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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

Find Flexible Fuel Vehicles…

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

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.

Owner's manual

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.

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

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)

View 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.
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