What does API in engine oil mean?
2 Answers
API in engine oil stands for the American Petroleum Institute, and the API grade of engine oil refers to the quality standards it specifies for engine oil. The functions of engine oil are: 1. To alleviate friction and high temperatures; 2. To reduce gas leakage and prevent external pollutants; 3. To prevent contact between water, air, acidic harmful gases, and parts; 4. To buffer the pressure rise in the engine cylinder port; 5. To flush away dirt generated on the working surfaces of parts. The method to check engine oil is: 1. Park the vehicle on a level surface; 2. After parking for 10 minutes, pull out the oil dipstick; 3. Hold the oil dipstick perpendicular to the ground to check.
API in motor oil stands for the American Petroleum Institute's classification standard. For someone like me who frequently tinkers with cars, seeing labels like API SP or SN on oil immediately tells me the performance level of the oil. API, which stands for American Petroleum Institute, grades oils based on testing, with SP being the latest standard that offers better engine cleanliness and wear protection. Older car models might be fine with SN or SM, but using outdated grades in modern vehicles can lead to carbon buildup or accelerated engine wear. By the way, API complements SAE viscosity ratings like 5W-30—one governs quality while the other governs flow characteristics. When choosing oil, always check your vehicle's manual for the specified API grade. Don't cut corners to save money, or you might end up with increased engine noise or, worse, costly repairs. Also, don't neglect oil change intervals—typically check every 5,000 to 8,000 kilometers. Maintaining the right API grade keeps your car running smoother.
