Gasoline engine, engine that uses gasoline as fuel. Gasoline engines are internal-combustion engines because the fuel, mixed with air, is burned inside the engine itself to produce hot gases that cause parts of the engine to move. These movements in turn cause other mechanical parts of the vehicle to operate. Gasoline engines power most transportation vehicles, such as cars, trucks, airplanes, and motorcycles, as well as lawn mowers, snowmobiles, and small tractors.
See also: Gasoline.