Little knowledge of engine oil

Choose correctlylubricating oil, First of all, we must understand the lubricant grade classification standard.

SAE (United StatescarThe Institute of Engineers uses the viscosity grade classification method. Owners can compare their own car's ambient temperature to choose engine oil. For example, SAE15W-40, 10W-40, 5W-50, the smaller the number before W, the lower the low temperature viscosity, and the better the protection ability of the engine during cold start; the number after W is the index of high temperature resistance of engine oil.

API (American Petroleum Institute) adopts the engine oil quality grade evaluation standard, and divides the lubricant into two categories: gasoline engine (S) and diesel engine (C). The lubricating oil for gasoline engines is represented by S, followed by an English letter (such as SE, SF, SH, SJ, SL, SM). The lower the alphabetical order, the higher the quality of the lubricating oil. At present, the highest level of SM grade is undoubtedly the top engine oil.