The selection of engine oil includes two aspects: viscosity level and quality level.

The choice of viscosity level: gasoline engine oil and diesel engine oil are basically the same.

Engine design requirements: Gasoline engines in the United States and Japan require the use of low viscosity grade engine oil. For example, Shanghai General Motors, Guangzhou Honda, and Fengshen Bluebird all require the use of 5W/30 viscosity grade engine oil; Most gasoline engines in Europe require the use of XW/40 viscosity grade engine oil. For example, Shanghai Volkswagen's vehicle oil is 5W/40 viscosity grade engine oil.

Environmental temperature requirements for use: For example, the minimum operating temperature for 15W/40 viscosity grade oil is -20 ℃, and the maximum operating temperature is 40 ℃. The minimum operating environment temperature for 40 viscosity grade oil is -5 ℃, and the maximum operating environment temperature is 50 ℃.

Requirements for engine operating conditions: For the same ambient temperature and engine, new cars should use oil with lower viscosity. Vehicles that have traveled 200000 kilometers or more can use oil with higher viscosity.