Diesel engines and gasoline engines differ, yet are the same in many ways. Both engines use the four- stroke system of intake, compression, ignition, and exhaust. Both are internal combustion engines, but one engine uses diesel fuel oil and the other uses gasoline. Gasoline engines use a spark plug to ignite a fuel-air mixture and a diesel uses superheated and highly compressed air. A diesel engine is equipped with glow plugs that heat the engine cylinder and allow for fuel ignition when the air and fuel mixture is sufficiently compressed. You'll usually find diesels in large trucks, buses, and a few autos and small trucks. Diesel engines generally provide an abundant amount of power without providing a lot of acceleration. Contact a qualified mechanic in your area for more information on diesel engines.