Automobiles have an internal combustion engine, and works with gasoline and gas oil as a fuel. Ethanol used as a fuel for the automobiles damages the fuel supply systems of the engines, rubbers, and plastics. This is because that the ethanol changes to sour, i.e. organic acid, which terribly damages the Al alloys, the rubbers and the plastics. Even bio diesel fuel (BDF), which is manufactured by esterification of used oil, makes gel during use. A promising electric vehicle after the decade has advantages and disadvantages, such as degradation of the batteries.
