The series beginning with S represents gasoline engine oil, and the specifications are SA, SB, SC, SD, SE, SF, SG, SH, SJ, and SL.

The series starting with C represents diesel engine oil, and the specifications are CA, CB, CC, CD, CE, CF, CF-2, CF-4, CG-4, CH-4, and CI-4.

When the two letters S and C exist at the same time, it means that the engine oil is universal for gasoline and diesel. From SA all the way to SL, with each letter increment, the performance of the oil will be better than the previous one, and there will be more additives in the oil to protect the engine. The further back the letters are, the higher the quality level. Among international brands, most engine oil grades are SF or above.

Extended information:

Notes:

1. When choosing engine oil, you must determine the use viscosity (SAE) and the corresponding (API) according to the instructions of the automobile manufacturer. ) quality level.

2. Under the condition of ensuring lubrication, try to choose engine oil with low (SAE) viscosity. Only choose high viscosity oil when the engine is worn.

3. Various brands of engine oil cannot be mixed due to different types of additives. Otherwise, the additives in the engine oil may react chemically and damage the effect of the lubricating oil.

4. Domestic engine oil is of high quality and low price, only 50-60% of the price of imported engine oil. Moreover, large domestic refineries can produce high-grade lubricants that meet international standards, so you can choose them with confidence.

Baidu Encyclopedia - Automobile Oil

Baidu Encyclopedia - Engine Oil Label