What Are the Oil Specifications?
2 Answers
Automotive engine lubricating oils are divided into two categories: S (gasoline engine oil) and C (diesel engine oil), with the following specifications: 1. Gasoline Engine Oil (S) Specifications: These are SA, SB, SC, SD, SE, SF, SG, SH, SJ, and SL. The SI specification is omitted to avoid confusion with the International System of Units abbreviation. 2. Diesel Engine Oil (C) Specifications: These are CA, CB, CC, CD, CD-II, CE, CF, CF-2, CF-4, CG-4, and CH-4. Among these, CD-II and CF-2 are for two-stroke diesel engines. The performance of CF and CD is similar, but CF has stricter engine testing requirements and a broader application range.
Oil specifications actually refer to the specific performance parameters of the oil. As an experienced driver with over a decade behind the wheel, I've learned the hard way. Last time I changed the oil, I didn't pay attention to the specifications and chose oil that was too thick. As a result, starting the car in winter became a real struggle, and I nearly damaged the engine. Later, I got smarter and realized that specifications include two parts: viscosity and grade. Viscosity represents the oil's flow characteristics at different temperatures. For example, in 5W-30, the "W" stands for winter performance at low temperatures—the smaller the number, the easier it is to start the engine. The "30" indicates high-temperature viscosity, which protects the engine at high speeds. The grade is classified by API standards like SN or SP—the higher the number, the better the oil quality and cleaning capability. When choosing oil, always refer to your vehicle's manual recommendations. Don't cheap out and buy no-name brands, as this can not only increase fuel consumption but also potentially cause engine problems. Now, I regularly check the oil dipstick and make sure the specifications match when changing the oil.
