Diesel engine

The diesel engine is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of air in the cylinder due to mechanical compression, rather than a spark, and so is also called a compression-ignition engine. German engineer Rudolf Diesel patented the design in 1893 and ran a working prototype under its own power in 1894; originally intended to replace stationary steam engines, the diesel engine went on to power submarines, ships, locomotives, trucks and generators, and achieves the highest thermal efficiency of any practical internal or external combustion engine.