Gear oil 80w90 and 85w140 which is better

Gear oil 85w140 is better. In China, the viscosity of gear oil for vehicles is divided into seven viscosity grades according to the viscosity classification specification of the British Society of Automotive Engineers (SAE), namely: 75W, 75W/90, 80W/90, 85W/90, 90 , 85W/140 and 140. The symbol of the oil viscosity grade of the gear. The W above represents the low temperature gear oil, and the number in front of the W represents the viscosity at low temperature. The number is proportional to the viscosity. The smaller the number, the smaller the viscosity, and the fluidity at low temperature. Better, the performance at low temperature will be stronger, the number after W represents the viscosity at high temperature, the number is proportional to the viscosity, the larger the number, the higher the high temperature viscosity, the higher the temperature resistance.

Gear oils can be divided into two types, namely: monopolar viscosity type and multi-grade viscosity all-day type. Unipolar viscosity type can be divided into two types, namely: high temperature type and low temperature type. The high temperature type has the mark of SAE90, the low temperature type has the mark of SAE75W, and the mark of the multi-level viscosity all-day type is 80w90, the multi-level viscosity all-day type is: gear oil 85w140 and 85w90, and the multi-level viscosity all-day type can be The applicable temperature range is stronger and wider.

The international standard requirement for kinematic viscosity of gear oil 80W90 is 13.5-24mm°/s. The international standard for the kinematic viscosity of 85W140 is 24-41mm°/s. Therefore, the viscosity of 85w140 is twice as high as that of 80w90. 80w90 is a gear oil suitable for winter use, and 85w140 is a heavy-duty gear oil more suitable for summer use.

Using high-grade gear oil can be used on vehicles with low requirements, but using low-grade gear oil can never be used on vehicles with high requirements. Such as: the gear oil on the hypoid can be used on the hypoid gear to lubricate it. It can also be used on common gear transmission parts to lubricate common gears. However, when the gear oil of ordinary vehicles is used on the transmission parts, it is not possible to use the hypoid gear lubricating oil, otherwise, the gear will be accelerated to wear.