Engine is not only applicable to power generation device, but also refers to the whole machine including power device (such as gasoline engine and aeroengine). The engine was first born in Britain, so the concept of engine also originates from English, and its original meaning refers to the kind of "mechanical device that generates power".

The diesel engine has better efficiency, so it can reduce carbon dioxide emissions, but the pollution is high (for example, long carbon chain organic compounds are prone to produce suspended particulates (SS) mainly composed of carbon particles after combustion); The use of high quality (ultra-low sulfur) diesel fuel and newer engine and pollution control technologies can reduce a lot of pollution, but until the latest technology can make diesel vehicles meet the environmental standards of the United States.