What does SN mean in motor oil?
2 Answers
In motor oil SN grade, the 'S' stands for gasoline or oil, and the 'N' represents the level. From A, B, C, D to N, the higher the letter, the higher the quality grade. SN is the motor oil with the best anti-wear effect. The functions of motor oil are as follows: 1. There is rapid relative sliding between the piston and cylinder, as well as between the main shaft and bearing bush. To prevent excessive wear of parts, an oil film needs to be established between the two sliding surfaces. A sufficiently thick oil film separates the surfaces of the relatively sliding parts, thereby reducing wear. 2. When the pressure at the engine cylinder port rises sharply, it suddenly increases the load on the piston, piston chips, connecting rod, and crankshaft bearings. This load is transmitted and lubricated through the bearings, cushioning the impact load.
The SN rating on this motor oil feels like giving the oil an identity tag, making it instantly clear which vehicles it's suitable for. SN is a quality classification standard developed by the American Petroleum Institute (API), specifically designed for gasoline engines. It gained popularity around 2010, representing that the oil provides higher protection levels—such as cleaning the engine interior, reducing sludge formation, and offering better resistance to high-temperature wear. For average car owners, choosing SN-grade oil means your beloved vehicle will be more durable and fuel-efficient, with fewer issues like shaking or sluggish acceleration. I always remind my friends that after switching to SN oil, regularly check the oil level and stick to the replacement cycle—typically every 8,000 to 10,000 kilometers is sufficient. This standard is also backward-compatible with older models, but don’t forget to check the user manual to confirm the matching grade during oil changes.
