A substance which, when added to gasoline, increases the amount of oxygen in the gasoline blend. Oxygenates include fuel ethanol, methanol and methyl tertiary butyl ether. Oxygenated gasoline formulated for use in most vehicles has oxygen content of 1.8% or higher by weight. Oxygenated fuels sometimes are mandated by the U.S. Environmental Protection Agency for sale and use in areas that exceed certain air quality standards.