Definition of diesel

The term "diesel" in reference to an engine type originated from the surname of a German engineer named Rudolf Diesel. In the late 19th century, Diesel developed a new combustion engine that operated by compressing air in the cylinder until it reached self-ignition temperatures, eliminating the need for a spark plug. This engine, known as the diesel engine, proved more efficient than traditional gasoline engines due to its higher compression ratios and use of a heavier, slower-burning fuel. The first diesel-powered vehicles were introduced in the early 1900s, and the diesel engine has since gained widespread popularity in a variety of applications, including transportation, industrial machinery, and electricity generation. The word "diesel" has since become a common noun in the English language, referring not only to the engine design, but also to the fuel used in those engines, which is a heavier, lower-volatility fuel than traditional gasoline.