Recently, a friend and the car editor discussed the car problem. Then ask, what grade is SG oil? Let's share our views. The first thing to know is that SG oil is basically the lowest oil. Its application scope is mainly in low-end cars, mini-cars and light gasoline pickup trucks. Most brands have the lowest SF grade, and SG is only one grade higher than SF. API stands for SG oil. API is the abbreviation of api gravity. API stands for the quality grade of engine oil and consists of two letters respectively. The first letter is S, which stands for gasoline engine and C stands for diesel engine. Marking S and C at the same time means that gasoline engines and diesel engines are basically universal. The second letter is from A to N in alphabetical order (gasoline has no I and K). With each letter added, the performance of the engine oil is basically better than the previous one, and there will be more additives in the engine oil to protect the engine. Therefore, the lower the second letter, the higher the quality level. Correspondingly, the price will be more expensive. The specifications of S series are APISA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM and SN. The specifications of C series are APICA, CB, CC, CD, CE, CF, CF-2, CF-4, CG-4, CH-4 and CI-4. Knowing this grade can help us choose the engine oil suitable for our car, thus protecting our engine.