How to Identify Engine Oil Grade?
2 Answers
To identify the engine oil grade, note that oil grades range from SA to SN, with this designation indicating the oil quality. The further the letter after 'S' is in the alphabet, the higher the oil quality. Engine oil grades are categorized as follows: 1. 'S' stands for gasoline engine oil, and 'L' represents the grade. The later the letter, the higher the oil grade. 2. 'C' stands for diesel engine oil, and 'F' represents the grade. Similarly, the later the letter, the higher the oil grade. The functions of engine oil include: 1. Reducing friction and high temperatures; 2. Minimizing gas leakage and preventing contamination from external pollutants; 3. Protecting against contact with water, air, and acidic harmful gases; 4. Cushioning the pressure rise in the engine cylinder; 5. Cleaning dirt generated on the working surfaces of components.
I always pay special attention to grade identification when changing the engine oil for my beloved car. The most straightforward method is to check the label on the front of the oil container—you'll see SAE viscosity codes like 5W-30 and API quality grade markings such as SP. These alphanumeric combinations actually represent the oil's low-temperature fluidity, high-temperature viscosity, and environmental standards. For example, my old German car requires 0W-40, while Japanese cars are more suited to 5W-30. Before maintenance, I recommend checking the vehicle manual to confirm the manufacturer's requirements. When purchasing oil, remember to verify the label on the container to avoid being tricked by sellers into using lower-grade oil.
