Ethanol is a renewable fuel made from various plant materials collectively known as “biomass.” More than 97% of U.S. gasoline contains ethanol, typically E10 (10% ethanol, 90% gasoline), to oxygenate the fuel and reduce air pollution.
Ethanol is also available as E85 (or flex fuel), which can be used in flexible fuel vehicles, designed to operate on any blend of gasoline and ethanol up to 83%. E85 is the term for motor fuel blends of 85 percent ethanol and 15 percent gasoline. Another blend, E15, is approved for use in model year 2001 and newer vehicles.
Tests have shown that E85 vehicles reduce harmful hydrocarbon and benzene emissions when compared to vehicles running on gasoline. Although carbon dioxide is released during ethanol production and combustion, it is recaptured as a nutrient to the crops that are used in its production. Use of ethanol results in low increases to the carbon cycle.