What is the Engine Oil Viscosity Grade Chart?
2 Answers
The viscosity grade of engine oil is closely related to the vehicle model and local temperature. Below is an introduction to vehicle models and grades: 1. Vehicle Models: Japanese cars primarily use low-viscosity oil, while German cars primarily use high-viscosity oil. 2. Grades: (1) 0W suitable temperature: -35°C (polar regions). (2) 5W suitable temperature: -30°C (northeast and northwest regions). (3) 10W suitable temperature: -25°C (central and southwestern parts of northern China). (4) 15W suitable temperature: -20°C (central and southwestern parts of northern China). (5) 20W suitable temperature: -15°C (areas south of the Yellow River and north of the Yangtze River). (6) 25W suitable temperature: -10°C (subtropical regions).
I found that the engine oil viscosity grade chart is actually the most important reference standard when choosing oil, just like checking sizes when buying clothes. This chart has SAE designations such as 5W-30 combinations, which I always refer to during oil changes. The first number, like 5W, represents low-temperature fluidity, which is especially critical for cold starts on winter mornings; the latter number, 30, indicates viscosity at high temperatures, preventing engine overheating during summer driving. Last month, while helping a friend check his car, I noticed he was using 20-weight oil, but his car was already ten years old. Older engines with increased clearances require 40-weight oil to form sufficient oil film protection. Using the wrong viscosity can easily lead to abnormal wear. I recommend checking the vehicle manual for the recommended grade before maintenance. New cars generally use low-viscosity oil for fuel efficiency, while older cars can appropriately increase viscosity.
