ETBE (Ethyl Tert-Butyl Ether) and MTBE (Methyl Tert-Butyl Ether) are oxygenated gasoline blending components used to raise octane and improve combustion. Both are produced by reacting isobutylene with an alcohol, but ETBE uses ethanol while MTBE uses methanol. These fuels from VP Racing are made to adhere to strict environmental standards as required in states like New York, Maine, Massachusetts, Colorado and Connecticut.