Born Mar. 18, 1858, in Paris; died Sept. 29, 1913. German engineer, known for creating an internal combustion engine with ignition caused by compression.

Diesel graduated from the Technical School in Munich in 1878. In patents obtained in 1892 and 1893, Diesel advanced the idea of creating an internal combustion engine operating on a cycle close to an ideal Carnot cycle; in this engine maximum temperature was to be obtained by compressing pure air to 25 meganewtons/m₂ (250 kilograms-force/cm₂). Diesel built an engine at Augsburg in 1897 based on the principle of preliminary air compression and self-ignition of the fuel, which was delivered into the cylinder at the end of the compression stroke. The engine had a relatively high efficiency but operated on expensive kerosine and had a number of design shortcomings. After several improvements were made in 1898–99, the engine began to operate dependably on cheap fuel—petroleum—and became widely used in industry and transportation.

Diesel drowned in the English Channel.