20th Century
- 1903 – The Exploration of Cosmic Space by Means of Reaction Devices was published by Konstantin Tsiolkovsky
- 1905 – Alfred Büchi patents the turbocharger. [13]
- 1913 – René Lorin invents the ramjet. [14]
- 1915 – Leonard Dyer invents a six-stroke engine, now known as the Crower six-stroke engine named after his reinventor Bruce Crower.
- 1926 – Robert H. Goddard launched the first liquid-fueled rocket. [15] [16]
- 1929 – Felix Wankel patents the Wankel rotary engine ( U.S. patent 2,988,008 ). [17]
- Late 1930s – Hans von Ohain [18] and Frank Whittle [19] separately build pioneering gas turbine engines intended for aircraft propulsion, leading to the pioneering turbojet powered flights in 1939 Germany and 1941 England.
- 1939 – The BMW company's BMW 801 aviation radial engine pioneers the use of an early form of an engine control unit, the Kommandogerät.
- 1940s – Ralph Miller patents his Miller cycle engine.
- 1954 – Felix Wankel creates the first working Wankel engine. [20]
- 1957 – Rambler Rebel announced Electrojector electronic fuel injection option, however no production models were offered with the option.
- 1964 – Ion engine invented. [21]
- 1966 – RD-0410 nuclear thermal rocket engine was ground-tested.
- 1960s – alternators replace generators on automobile engines. [22]
- 1970s – electronically controlled ignition appears in automobile engines.
- 1975 – Catalytic converters are first widely introduced on production automobiles in the US to comply with tightening EPA regulations on auto exhaust.
- 1980s – electronically controlled ignition improved to reduce pollution.
- 1980s – electronic fuel injection appears on gasoline automobile engines.
- 1989 – The Bajulaz Six-Stroke Engine was invented by the Bajulaz S A company, based in Geneva, Switzerland; it has U.S. patent 4,809,511 and U.S. patent 4,513,568 .
- 1990s – Hybrid vehicles that run on an internal combustion engine (ICE) and an electric motor charged by regenerative braking.