How to Read Engine Oil Grades?
2 Answers
Engine oil grades can be identified as follows: 1. Oil Quality: The first is the evaluation standard for oil quality grades set by the American Petroleum Institute (API). S stands for gasoline engine oil. L represents the grade, ranging from API SA, SB, SC, SE, SF, SG, SH, SJ, SL, SM—the further the letter in the alphabet, the higher the oil quality. SL is currently the highest-quality engine oil in the world. C stands for diesel engine oil. F represents the grade, ranging from API CA, CB, CC, CD, CE, CF, CF-4, CG-4, CH-4—the further the letter, the higher the oil quality. 2. Oil Viscosity: The second is the standard by the Society of Automotive Engineers (SAE), also known as the measure of oil viscosity, which can be divided into single-grade and multi-grade viscosities. For example: SAE 15W-40, SAE 5W-40. "W" stands for winter, and the smaller the number before it, the better the oil's low-temperature fluidity, indicating a lower usable environmental temperature and better engine protection during cold starts. The number after the "W" (after the hyphen) indicates the oil's high-temperature resistance—the larger the number, the better the oil's protective performance under high temperatures.
I used to think oil grades were a mystery, like reading hieroglyphics. But it's actually not that complicated. The key is to look for the combination of numbers after the SAE letters on the oil bottle label, such as the common 5W-30. The 5W indicates the viscosity grade in winter—a smaller number means easier engine starts in cold weather. The 30 represents viscosity at high temperatures—a larger number provides better protection for engine components. When choosing, always consider the specifications recommended in your vehicle's manual—don't just pick randomly, or you might end up with louder engine noise or higher fuel consumption. Before an oil change, I always check the bottle label to ensure the code is clearly visible, avoiding counterfeit products that could harm my car's lifespan. Overall, learning to read this is simple—just a quick glance ensures the oil matches your car's needs, reducing wear and tear issues.
