Engine oil, also known as engine lubricating oil, is an indispensable and important oil in vehicles. In addition to its well-known functions of lubrication and wear reduction, it can also assist in cooling, sealing and leak prevention, rust prevention, corrosion prevention, shock absorption and buffering. Without it, the engine is prone to blowby, severe rust, melting, and even direct scrapping.

Like other fluids in vehicles, engine oil also has an oil change cycle, and it cannot be completely changed without adding it at once. During use, engine oil can also undergo oxidation, acidification, and dissolution of sludge, which not only causes the engine oil to lose its protective effect on the engine, but also corrodes the engine, blocks oil pipelines, fails lubrication, heat dissipation, and causes engine scrapping.

Of course, the more frequent the oil change, the better. After all, the cost of using the car is also a major concern for car owners. In general, the oil change interval is closely related to the engine brand, oil quality, and vehicle operating conditions.

If the car owner is using original factory oil, then follow the vehicle's maintenance manual for operation, or refer to the recommended oil change mileage at the service station. If the car owner is using non original engine oil, they can refer to the oil change interval marked on the oil used appropriately, and judge the oil change interval based on their actual usage conditions:

There are many indicators for selecting engine oil, such as oil grade, viscosity, flash point, sulfate content, pour point, total alkalinity, etc., which makes many car owners unsure how to choose. Actually, we just need to focus on the grade and viscosity on the outer packaging of the engine oil.

In general, the oil grade mark is API, which is the abbreviation of the American Petroleum Institute. The label after API is the quality grade of the oil; The series starting with "S" are used for gasoline engines, while the series starting with "C" are used for diesel engine series. If "S" and "C" coexist, it indicates that this is a universal engine oil for gasoline and diesel engines. The oil used in diesel engines can be divided into CA, CB, CC, CD, CE, CF, CF-2, CF-4, CG-4, CH-4, CI-4, etc. The later the letter, the higher the quality level. Generally, CK-4 is not a problem for Chinese VI diesel engines.

The viscosity mark of engine oil is SAE, which is the abbreviation of the American Society of Automotive Engineers. The label after SAE indicates the viscosity value of the engine oil, such as "SAE 5W-40", where "W" is the abbreviation of "WINTER", indicating that this type of engine oil is suitable for use at low temperatures, and oil without "W" is suitable for use at high temperatures; The number before "W" represents the pour point temperature, which is simply the freezing point temperature. The shorter the number, the better the low-temperature fluidity of the engine oil, and the lower the available temperature for use; The number after "W" represents the kinematic viscosity of the oil at 100 ℃. The higher the value, the higher the viscosity. However, this is only a symbol to distinguish the viscosity of the oil and does not equate to ambient temperature. This is something that cars should pay special attention to.

When choosing engine oil, it is generally not a problem to follow the engine oil model provided in the vehicle manual. Of course, it is best to choose a more reliable brand and not only seek cheap prices. If you are really not confident, you can directly choose original factory engine oil, which is also a labor-saving and safe approach.