What does gear oil 85w140 mean?
2 Answers
Automotive gear oil 85w-140 indicates that the gear oil is a multi-grade oil, with two grades of 85W and 140, suitable for ambient temperatures ranging from -26 to +50. The relevant introduction is as follows: 1. The SAE viscosity classification divides gear oil into grades such as 75W, 80W, 85W, 90, 140, and 250. 2. Gear oil is a high-viscosity lubricant specifically designed to protect transmission power components, typically accompanied by a strong sulfur odor. Vehicle gear oil is classified by performance and viscosity. Currently, the American Petroleum Institute (API) performance classification and U.S. military gear oil specifications are widely adopted worldwide. Most manual transmission lubricants and differentials use hypoid gear oil. These contain extreme pressure (EP) additives and anti-wear additives to handle the action of hypoid bevel gears.
85w140 gear oil refers to the SAE viscosity grade. 85W represents the low-temperature startup viscosity, where a smaller number indicates better fluidity in cold weather and easier starting. 140 is the high-temperature viscosity, indicating higher viscosity at high temperatures to better protect gears from wear. If the wrong oil is selected, such as using a high W-number oil in cold regions, starting will be difficult. Remember to check the vehicle manual for recommended specifications and avoid using cheap, low-quality oil, as it can lead to premature gear damage. Regular oil changes are crucial—I generally recommend changing every 50,000 kilometers or two years to keep the transmission running smoothly. The high viscosity of 140 is especially useful for long-term off-roading or heavy towing.
