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Biofuels explained Use of ethanol

Ethanol as a transportation fuel

did youknow


The Ford Model T had an engine capable of running on either gasoline or ethanol.

E10 and E15

The most common use of ethanol as a fuel is in mixtures of motor gasoline. Most of the gasoline sold in the United States contains some fuel ethanol. The exact amount may vary by region. In general, the ethanol content of motor gasoline does not exceed 10% by volume. Gasoline with 10% ethanol content is referred to as E10, and gasoline with 15% ethanol content is called E15. All gasoline vehicles can use E10. Currently, only light-duty vehicles with a model year 2001 or newer can use E15.

The U.S. Environmental Protection Agency (EPA) is responsible for developing and implementing the U.S. Renewable Fuel Standard (RFS) Program to ensure that transportation fuel sold in the United States contains a minimum volume of renewable fuel. EPA is developing processes and procedures for how ethanol blends greater than E10 can be sold at retail.

gasoline pump

Nearly all gasoline sold in the United States contains ethanol.

Source: Stock photography (copyrighted)

E15 label

Pump label required for E15.

Source: U.S. Environmental Protection Agency (public domain)


E85 is a gasoline-ethanol blend containing 51% to 83% ethanol, depending on geography and season, and is defined as an alternative fuel. Although most E85 use in the United States occurs in the Midwest, about 3,625 public E85 fueling stations are located around the country. Only flexible-fuel vehicles can use E85.

Flexible-fuel (flex-fuel) vehicles can run on any mixture of ethanol and gasoline up to E85. Flex-fuel vehicles may have a badge or plaque on the body of the vehicle with terms such as E85, Flex Fuel, or FFV.

Last updated: June 24, 2020