What is the Engine Oil Viscosity Grade Chart?
4 Answers
The viscosity grade of engine oil is closely related to the vehicle model and local temperature, indicating the ambient temperature. Specific details are as follows: 1. Vehicle Model: Japanese cars primarily use low-viscosity oil, while German cars prefer 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 (north-central and southwest regions). (4) 15W suitable temperature — -20°C (north-central and southwest regions). (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).
The engine oil viscosity grade chart is essentially a reference guide to help car owners understand how oil performs at different temperatures, much like those numerical codes on oil labels, such as 5W-30—something I've learned over a decade of driving. The 'W' stands for winter temperature, and the smaller the number before it, the thinner the oil is in cold weather, making the car easier to start. The number after indicates viscosity at high temperatures, with a higher number offering better protection for the engine internals. I always check this chart before an oil change and adjust my choice based on local climate—using 5W or 0W in colder winters and opting for higher numbers like 20 or 30 in hot summers. This not only saves fuel and reduces emissions but also extends engine life. Ignoring it can lead to hard starts or skyrocketing fuel consumption, so never pick oil based solely on price—always match the standards recommended in your vehicle's manual carefully.
For me, the motor oil viscosity grade chart is a crucial tool for engine maintenance, akin to a simple cipher. Based on the SAE standard, it clearly categorizes the temperature characteristics of motor oil: for example, in 10W-40, the first number reflects cold-weather fluidity—a lower value ensures smoother starts, while the latter number indicates high-temperature protection thickness—a higher value prevents wear. Having seen numerous repair cases, I know choosing the wrong viscosity can lead to engine knocking or unstable oil pressure, especially in regions with variable climates. Proper use of this chart helps avoid such issues, and regularly checking the oil condition has become part of my routine.
When I first learned about the engine oil viscosity grade chart, I realized it's essentially the explanation panel for the label on the oil can, such as 0W-20. The smaller number before the W indicates better cold-start performance in winter, while the larger number after it suggests stronger protection in hot weather. This is quite useful for beginners—choosing the right viscosity can improve driving smoothness and prevent unnecessary fuel consumption or mistakes.
