What is the difference between SJ and SN engine oil?

[DelFrancisco]

SN has a higher performance rating than SJ. The 'S' stands for gasoline engine oil (if it were 'C', it would be diesel engine oil), and the following letters range from A to N, with later letters indicating higher performance levels. Therefore, SN is superior to SJ. The oil quality is graded from low to high as follows: SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, and SN. Below is some relevant information about engine oil: 1. Function of engine oil: Engine oil lubricates and reduces friction in the engine, aids in cooling, seals against leaks, prevents rust and corrosion, and cushions shocks. It is often referred to as the 'blood' of a car. Choosing the right oil and changing it regularly helps maintain the engine in good condition and extends its lifespan. 2. Choosing engine oil: The best oil isn't necessarily the most expensive; rather, the right oil should be selected based on the characteristics of the car's engine and the driver's habits. Engine oil can also be categorized for winter and summer use. For winter, the primary consideration is the low-temperature viscosity grade, while in summer, when temperatures are high, there's no need to choose oil with a superior low-temperature viscosity grade.