Gasoline fuel additives such as ethanol, ETBE, or MTBE that add extra oxygen to gasoline to reduce carbon monoxide pollution produced by vehicles.
Any substance that when added to motor gasoline increases the amount of oxygen in that gasoline blend. Includes oxygen-bearing compounds such as ethanol, methanol, and methyl-tertiary-butyl-ether. Oxygenated fuel tends to give a more complete combustion of carbon into carbon dioxide (rather than monoxide), thereby reducing air pollution from exhaust emissions.
Liquid organic compounds that can be blended into gasoline to increase its oxygen content; during combustion, this additional oxygen reduces the output of CO and may reduce emissions of ozone-forming materials. The two major oxygenates in use today are ethanol and MTBE.