What Level is SN Engine Oil?
1 Answers
SN-grade engine oil is the second highest grade. Engine oils starting with "S" are specifically for gasoline engines and cannot be used in diesel vehicles. Below are relevant details: 1. Classification of engine oil: Currently, the main engine oils still in use for gasoline vehicles are SJ, SL, SM, and SN. In the API quality grades, SN-grade is the second highest grade for gasoline engine oils, while SP is the highest. 2. Factors in choosing engine oil: When selecting engine oil, one should not only consider which vehicles SN-grade oil is suitable for but also its viscosity. Even within the same SN grade, there can be different viscosity indexes. The viscosity determines the oil's performance at high and low temperatures, with low-temperature flow characteristics and high-temperature viscosity dictating the oil's applicable range. 3. Different grades of engine oil should not be mixed: Since engine oils contain different chemical components, mixing them may cause the oil to degrade, failing to provide lubrication and leading to component wear. Therefore, if a vehicle owner needs to change the oil grade, the old oil must be completely drained. Additionally, although SN-grade oil performs well, it is most suitable to choose the grade specified by the engine manufacturer. If urban environmental protection is a priority, using a higher-grade oil is naturally better.