Diesel vehicles are similar to gasoline vehicles because they both use internal combustion engines. One difference is that diesel engines have a compression-ignited injection system rather than the spark-ignited system used by most gasoline vehicles. In a compression-ignited system, the diesel fuel is injected into the combustion chamber of the engine and ignited by the high temperatures achieved when the gas is compressed by the engine piston. http://www.genourpowergenerator.com/engine/diesel-engine/13hp-diesel-engine.html