What Are the Standards and Classifications of Engine Oil?
1 Answers
The classification of engine oil typically follows two methods: viscosity grading and oil quality grading. Here are the detailed explanations: 1. SAE Viscosity Grading: According to the viscosity classification method, lubricating oils are divided into three types: high-temperature type for summer, low-temperature type for winter, and all-season type suitable for both winter and summer. (2) High-temperature type for summer: 20, 30, 40, 50. The larger the number, the higher the viscosity, and the higher the maximum applicable temperature. (2) Low-temperature type for winter: 0W, 5W, 10W, 15W, 20W, 25W. The symbol W stands for Winter, and the smaller the number before W, the lower the low-temperature viscosity, the better the low-temperature fluidity, and the lower the minimum applicable temperature. (3) All-season type: 5W-20, 5W-30, 5W-40, 5W-50, 10W-20, 10W-30, 10W-40, 10W-50, etc. The smaller the number before W, the lower the minimum applicable temperature of the oil, and the larger the number after W, the higher the maximum applicable temperature. Since this type of oil is suitable for various operating conditions, all-season oil is widely used and recommended by major automobile manufacturers. 2. Oil Quality Grading: API engine oils are divided into two categories: one is oil starting with S, which is suitable for gasoline engines, and the other is oil starting with C, which is suitable for both gasoline and diesel engines. (1) Oil starting with S: This type of oil starts with S, and the letters range from A to N. Each subsequent letter represents a higher grade than the previous one. For example, SN is a higher grade than SM. (2) Oil starting with C: This type of diesel engine oil follows a similar grading system as the S-grade oil. The further the letter is in the alphabet, the higher the oil grade.
