Diesel is a light petroleum product, a complex mixture of hydrocarbons (with a carbon atom number of about 10-22), used as fuel for diesel engines. It is mainly composed of diesel fractions produced through processes such as crude oil distillation, catalytic cracking, thermal cracking, hydrocracking, and petroleum coking. It can also be produced through shale oil processing and coal liquefaction, and can be divided into two categories: light diesel (with a boiling point range of about 180-370 â??) and heavy diesel (with a boiling point range of about 350-410 â??). Widely used in large vehicles, railway locomotives, and ships. The most important use of diesel is for diesel engines in vehicles and ships. Compared with gasoline engines, diesel engines have higher thermal efficiency and lower fuel consumption. Diesel has low energy consumption, so some small cars and even high-performance cars have switched to diesel.