Engine cooling systems are an integral part of an automobiles engine. They perform the important task of keeping the engine parts cool and working at an optimal temperature. Radiators are used for cooling internal combustion engines mainly in automobiles, but also in piston-engined aircraft, railway locomotives, motorcycles, stationary generating plants, or any similar engine. In automobiles with a liquid-cooled internal combustion engines, a radiator is connected to channels running through the engine and cylinder head through which a liquid (coolant) is pumped. The radiator transfers the heat from the fluid inside to the air outside, thereby cooling the fluid, which in turn cools the engine.