The largest single use of ethanol is as an engine fuel and fuel
additive. More than any other major country, Brazil relies on
ethanol as an engine fuel. Gasoline sold in Brazil contains at least
25% anhydrous ethanol. Hydrous ethanol (about 95% ethanol and
5% water) can be used as fuel in more than 90% of new cars sold in
the country. The US uses Gasohol (max 10% ethanol) and E85 (85%
ethanol) ethanol/gasoline mixtures. Ethanol may also be utilized as
a rocket fuel and in lightweight rocket-powered racing aircrafts
[85]. The Australian law limits the use of pure ethanol sourced from
sugarcane waste to 10% in automobiles. It has been recommended
that older cars (and vintage cars designed to use a slower burning
fuel), should have their valves upgraded or replaced [86].