Engine oil, engine oil, English name :Engine oil. The density is about 0.91×10³(kg/m³), which can play the role of lubrication and wear reduction, auxiliary cooling and cooling, sealing and leakage prevention, rust prevention and corrosion prevention, shock buffering and so on. It is known as the "blood" of the car.

Oil consists of two parts: base oil and additive. Base oil is the main component of lubricating oil, determines the basic properties of lubricating oil, additives can make up for and improve the lack of performance of base oil, give some new properties, is an important part of lubricating oil.

The engine is the heart of the car, there are many metal surfaces in the engine that rub against each other, these parts move fast, the environment is poor, and the operating temperature can reach 400°C to 600°C. Under such harsh conditions, only qualified lubricating oil can reduce the wear of engine parts and extend the service life.