A diesel engine is a heat engine that uses diesel fuel to convert chemical energy into mechanical energy. Diesel engines ignition are different from gasoline engines, and the mixture in the cylinder of  diesel engines are compressurized, not ignited. Gasoline engines generally inject gasoline into the intake pipe and mix it with air to become a combustible mixture and then enter the cylinder and combustion and expansion through spark plug ignition.

• The diesel engine is generally injected directly into the engine cylinder by the injection pump and the fuel injection nozzle, and the compressed air in the cylinder is evenly mixed, spontaneously combusted at high temperature and high pressure, and pushes the piston to do work.
• The economic performance of the diesel engine is good, and it can produce greater torque under the same displacement. However, compared with the gasoline engine, the volume is large, the working noise is large, and the manufacturing cost is higher than the gasoline engine, it is not easy to maintain, it is more difficult to start cold in winter, and the emission of carbon soot and particles is more.
• The economic performance of the diesel engine is good, and it can produce greater torque under the same displacement. However, compared with the gasoline engine, the volume is large, the working noise is large, and the manufacturing cost is higher than the gasoline engine, it is not easy to maintain, it is more difficult to start cold in winter, and the emission of carbon soot and particles is more.