What is the difference between 5w40 and 0w40?

[JohnnyMarie]

The difference between 5w40 and 0w40 lies in their ability to withstand different minimum temperatures: 1. The number before the 'w' represents the minimum temperature the oil can withstand. A smaller number indicates lower low-temperature viscosity, better low-temperature fluidity, and a lower applicable minimum temperature. Both 5w40 and 0w40 have the same high-temperature viscosity performance, but 0w40 oil has better low-temperature viscosity and fluidity, allowing it to adapt to colder temperatures, down to -35°C, whereas 5w40 can only withstand temperatures as low as -30°C. 2. Oil with a lower number before the 'w' makes it easier to start the engine in cold weather. For northern regions, 0w40 oil is more recommended, while in southern regions, where low-temperature performance is less critical, one can choose the appropriate oil grade based on personal needs.