What is the difference between 10w30 and 5w30?

[ZoeyFitz]

The main difference between 10w30 and 5w30 lies in their low-temperature fluidity. The smaller the number before "W," the lower the low-temperature viscosity and the better the cold resistance. SAE stands for the Society of Automotive Engineers. 10W30 and 5W30 are two viscosity grades under this standard. The minimum operating temperature for 10W30 is approximately -25°C, while 5W30 can function at -30°C, meaning the latter has better low-temperature fluidity and cold resistance. The "30" refers to the viscosity at 100°C, with higher numbers indicating higher viscosity and better high-temperature resistance. Excessive viscosity can make engine cold starts difficult, reduce cleaning efficiency, and clog oil passages. Conversely, insufficient viscosity can lead to poor cylinder sealing, reduced power output, and increased oil consumption. Therefore, selecting the appropriate viscosity is crucial for engine performance. It is generally recommended to follow the manufacturer's manual for oil viscosity selection, and individuals should not adjust it arbitrarily. As the vehicle's mileage increases and component wear becomes more pronounced, switching to a higher viscosity oil may be considered.