5. Advanced innovations in piston engines

5.1 State of the art

In his 1799 patent, Philippe Lebon predicted that "hydrogen gas", a wood gas containing at least 50% dihydrogen, would be "a force applicable to all kinds of machines". In 1859, Étienne Lenoir patented "un moteur à gaz et à air dilaté", a 2-stroke internal combustion engine using coal gas. From 1980 onwards, Japanese carmaker Mazda worked on the application of dihydrogen to rotary engines, and in 1991 presented a hydrogen-powered rotary engine concept at the Tokyo Motor Show. The BMW Hydrogen 7, presented at the Los Angeles Auto Show in November 2006, is said to be the first hydrogen-powered production car. BMW produced around 100 examples of the Hydrogen 7 between 2007 and 2009. The vehicle was equipped with a 6-liter V12 engine, running on both gasoline and...