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.

[LeOscar]

I've read a lot of car maintenance materials, and the main difference between 5w40 and 0w40 lies in the number before the W. W stands for winter, with 0w capable of easily starting the engine at temperatures below -35°C because the oil is thinner and flows more easily, while 5w is only suitable for around -30°C. The latter part, 40, indicates the same viscosity at high temperatures, meaning there's no difference in engine protection during hot weather. Therefore, if you live in cold regions like the Northeast or mountainous areas, 0w40 is the preferred choice for quicker ignition and reduced starting difficulties. However, in warmer southern regions, 5w40 is sufficient, being both economical and practical. Remember to choose oil based on the season and region, otherwise, slow cold starts in winter can increase engine wear.

[LeChristopher]

I've driven for over a decade and used different engine oils in extremely cold regions. With 5w40, there's noticeable startup lag in frigid temperatures, accompanied by engine knocking sounds. After switching to 0w40, ignition completes instantly, the car runs smoother, and fuel efficiency improves slightly. The key is that both maintain the same high-temperature viscosity of 40, providing equal engine protection in hot weather. The difference lies in cold-weather performance: 0w40 performs down to -40°C, while 5w40 only handles -30°C. Therefore, northern drivers should prioritize 0w40 to avoid winter breakdowns, while southern drivers can choose either without issues.

[OSara]

Simply put, the difference between 5w40 and 0w40 lies only in the first number. 0w indicates easier cold starts with better oil fluidity at low temperatures. The second number 40 provides identical engine protection in hot weather. Therefore, if you're in a cold climate, 0w40 facilitates better ignition; in warmer regions, 5w40 performs perfectly well. Always check your owner's manual for the recommended oil specification.