The most common way to power an automobile at the moment, at least, is with an Otto-cycle engine. The Otto cycle is a description of a repetitive thermodynamic process where a flammable gas is compressed inside a chamber (say, a cylinder), ignited, forcing the chamber to expand and producing heat, then the chamber contracts again, expelling the gaseous results of the ignition and also excess heat, followed by an expansion of the chamber that serves to allow another amount of flammable gas in. There are four phases, and if you build your cylinder so it includes a tight-fitting movable piston, the piston makes four “strokes” — two reducing the volume in the cylinder, and two expanding it. Another name for the Otto cycle engine is a “four-stroke” engine.
“Otto cycle” is probably the preferred name, at least in engineering circles, because it recognizes Nicolaus Otto, who was born June 10, 1832 in the Duchy of Nassau, an area of what is now Germany.
Otto was a very bright student; he began school when he was about 6, and by the time he was 12 was promoted to high school. He was interested in science in school, but instead became an apprentice in a merchandising company and became a grocery salesman. He specialized in “colonial goods” — that is, imported products like coffee, tea, sugar, and rice.
Then when he was about 28, he read about an engine built in Paris by Jean Lenoir. It used a gas similar to natural gas as fuel. Otto and his brother built their own version of it, and applied for a patent. They didn’t get the patent; their engine wasn’t deemed original enough. Otto’s brother quit the project. Otto persisted, though, and got a new partner, Michael Zons, who was a mechanic. He kept his job as a grocery salesman, and funded the experiments himself.
He ran low on funds, though, and in 1864 convinced an investor, Eugene Langen, to be his partner. He probably knew Langen because Otto was a sugar salesman, and Langen’s father owned a large sugar company. They formed the NA Otto & Cie company in March, 1864 in Cologne. It was the first company to focus on designing and producing internal-combustion engines. Their first engine was more than twice as efficient as the Lenoir engine, and was a commercial success. By 1875 they were building over 600 engines per year. These were stationary engines that would be used in a workshop or factory.
Their customers needed a more powerful version, though, and Otto returned to an idea he’d tried back in 1862: the four-stroke cycle. NA Otto & Cie was by 1875 a thriving, well-known company, and had hired two more engineers, Franz Rings and Herman Schumm, and with their collaboration Otto introduced a new engine in 1876. It was the first Otto cycle engine. It was much more powerful and usable than their previous product, and they went on to produce 17,000 of them. Among the users was Gottlieb Daimler, who installed a version in a moving vehicle, and with Karl Benz built the first modern automobile. Daimler, by the way, worked in Otto’s company for a while.
Otto’s home is now a museum you can visit, and every time you ride in a gasoline-powered car, you can recall that the motive power is provided by an Otto-cycle engine.