What is the method for distinguishing automotive oil grades?

[McSophia]

Automotive oil grades are distinguished as follows: 1. The 'S' series represents oil for gasoline engines; 2. The 'C' series represents oil for diesel engines; 3. If both 'S' and 'C' letters are present, it indicates that the oil is suitable for both gasoline and diesel engines. The functions of engine oil are: 1. To alleviate friction and high temperatures; 2. To cool and reduce temperature; 3. To clean and remove contaminants; 4. To dampen vibrations and cushion impacts; 5. To prevent rust and corrosion. Engine oil, also known as engine lubricant, can have the following impacts when using inferior quality oil: 1. It degrades the quality of the oil, reducing its performance; 2. It disrupts the lubrication of precision components such as fuel pumps and injectors; 3. It decreases the power output of the generator set; 4. It affects the combustion efficiency of the engine.