How to Identify Engine Oil Grades?

[LeEverly]

Methods to distinguish engine oil grades: 1. Engine oil grades are classified by quality level and viscosity level. Oil for gasoline engines is usually denoted by the letter "S", while oil for diesel engines is usually denoted by the letter "C". 2. Engine oil consists of base oil and additives, where the base oil is the main component of the lubricant, determining its basic properties, and additives can improve the shortcomings of the base oil. 3. The specifications for the "S" series include: SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL. 4. The specifications for the "C" series include: CA, CB, CC, CD, CE, CF, CF-2, CF-4, CG-4, CH-4, CI-4. 5. Generally, as the letters increase, the grade of the oil also becomes higher. When both letters appear, it indicates that the oil is universal and can be used for both gasoline and diesel engines. 6. For viscosity, the SAE designation is commonly used, for example: 10W-40. The "W" stands for winter, and the number before the letter represents the oil's fluidity—the smaller the number, the better the fluidity.