What does SN stand for in engine oil?

[StKatherine]

SN in engine oil represents a high-quality grade of engine oil. The functions of engine oil are: 1. To reduce friction and high temperatures; 2. To cool down the engine; 3. To clean and remove contaminants; 4. To cushion and absorb shocks; 5. To prevent rust and corrosion. Engine oil, also known as motor lubricant, is composed of base oil and additives. The base oil is the main component of the lubricant, determining its fundamental properties, while additives compensate for and improve any deficiencies in the base oil's performance. The method for changing car engine oil is: 1. Use a jack to lift the vehicle, locate the drain plug, and unscrew it to drain the oil; 2. After removing the oil filter, place a container underneath it; 3. Replace with a new oil filter and add new engine oil.