What is the difference between gear oil 85w90 and 80w90?

[MacKate]

85w90 and 80w90 differ in their low-temperature viscosity. While both 85w90 and 80w90 have the same high-temperature viscosity, 80w90 has a lower low-temperature viscosity compared to 85w90, resulting in better fluidity of the gear oil. This allows it to be used at lower temperatures and provides superior low-temperature performance. Below are the details: Classification of gear oil: Gear oil can be divided into single-grade viscosity type and multi-grade all-weather type. Single-grade viscosity type can be further classified into high-temperature type and low-temperature type. Explanation of gear oil labeling: The "W" in the viscosity grade label of gear oil indicates low-temperature type gear oil. The number before the "W" represents the low-temperature viscosity—the smaller the number, the lower the viscosity, resulting in better fluidity and superior low-temperature performance. The number after the "W" represents the high-temperature viscosity—the larger the number, the higher the high-temperature viscosity, allowing it to withstand higher temperatures.