Louisiana defines gasohol to mean a fuel that contains not more than ninety percent gasoline and at least ten percent ethanol. Ethanol is ethyl alcohol. The law has been interpreted to mean that 100 percent of the feedstocks must be from Louisiana farmers. Ethanol is one of a series of chemicals called oxygenates which have begun to be added to gasoline as octane enhancers as lead has been phased out. These chemicals are called oxygenates because they have oxygen in their molecular makeup.
Ethanol is the only one made from agricultural products such as grain or sugarcane molasses.
Only ethanol fermented from agricultural products receives a subsidy from Louisiana or the federal government. MTBE is in widespread use throughout the U.S. and Europe as an octane enhancer in gasoline. Methanol has received a lot of attention because it is cheap. However, methanol is corrosive and will attack plastic fuel system components if the system is not specifically designed to handle methanol. Methanol has long been a preferred fuel for racing engines because of the higher compression ratios at which methanol may be burned relative to gasolines.