What does the SF in engine oil represent?
1 Answers
Engine oil S represents gasoline engine oil, and F represents the quality grade. The following are the specific introductions to engine oil grades: 1. C stands for diesel engine oil: from CA, CB, CC, CD, CE, CF, CF-4, CG-4, CH-4, CI-4, CJ-4, the further back the letters are arranged, the higher the oil quality grade. Generally, diesel engines use CD-grade oil, while turbocharged diesel engines require higher oil quality. -4 indicates that the oil is suitable for 4-stroke diesel engines. 2. S stands for gasoline engine oil: API engine oils are divided into two categories. The S series represents oils for gasoline engines, with specifications including SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN. When both S and C letters are present, it indicates that the oil is suitable for both gasoline and diesel engines. SN-grade is currently the highest grade of engine oil. SJ was the standard in the 1990s, SL was the standard in 2001, SM was the standard in 2004, and SN was the standard in 2010.