The difference between 85w90 and 80w90

The viscosity of gear oil is based on the SAE viscosity classification method, which is 70W, 75W, 80W, 85W, 90, 140, 250 seven viscosity grades, and different viscosity grades are selected according to the seasonal temperature.What are the differences between the 85w90 and 80w90 we are talking about today? For those who are new to automotive knowledge, they may still be a bit confused.

First of all, the smaller the number on the front of W, the lower the low-temperature viscosity, the better the fluidity of the gear oil, it can be used at lower temperatures, and the low-temperature performance is stronger, so in winter, it is easier to shift the gear in a cold car. In general, the main difference between 85w90 and 80w90 is the difference in low temperature viscosity, but their high temperature viscosity is the same (90 mark). So when we choose the model, we must not only strictly follow the regulations of the vehicle instruction manual, but also pay attention to the local climate, otherwise too high or low will have an impact.

Too high viscosity:

If the gear oil viscosity is too high, it will not only affect the effect of low-temperature starting, but also increase the running resistance of the engine, which has a certain impact on both power and fuel consumption.

Viscosity is too low:

If the viscosity of the gear oil is too low, it is easy to cause the oil film to crack or decrease in strength, which will increase the wear resistance of the bearing and reduce the service life of the bearing to a certain extent.