E85 is an alcohol fuel mixture of 85% ethanol and 15% gasoline, by volume. ethanol derived from crops (bioethanol) is a biofuel.
E85 as a fuel is widely used in Sweden and is becoming increasingly common in the United States, mainly in the Midwest where corn is a major crop and is the primary source material for ethanol fuel production.
E85 is usually used in engines modified to accept higher concentrations of ethanol. Such flexible-fuel engines are designed to run on any mixture of gasoline or ethanol with up to 85% ethanol by volume.