Is There a Difference Between Gear Oil and Engine Oil?
2 Answers
Gear oil and engine oil are different, mainly reflected in the following aspects: 1. Different working environments: Gear oil is primarily used in manual transmissions, reducers, and differentials, while engine oil is mainly used in car engines. Since gear meshing involves line contact, gear oil must have extremely high viscosity to form an oil film at the gear meshing points. In contrast, engine lubrication involves mostly surface contact, without the extreme high pressure generated during gear meshing, so its viscosity requirements are relatively lower. 2. Different emphases: Gear oil focuses on protecting gears under high temperatures, while engine oil emphasizes its fluidity at low temperatures. Additionally, gear oil is strongly alkaline, whereas engine oil is weakly alkaline. 3. Engine oil and gear oil must never be mixed, as this can easily prevent machinery from achieving optimal lubrication, leading to damage.
Yes, gear oil and engine oil are indeed different, as I've learned from working on my own car. Gear oil is primarily used in transmissions and differentials, designed to be thicker to withstand high-pressure friction and protect the gear system. Engine oil, on the other hand, is specifically for the engine, with lower viscosity, and besides lubrication, it also helps cool engine components and handle combustion residues. For example, driving a manual transmission car means I need to regularly check the gear oil in the transmission, typically changing it every two to three years; whereas engine oil needs to be replaced every six months, otherwise the engine can overheat and get damaged. Mixing them up can lead to unusual noises while driving and potentially major failures. I remember once helping a friend change his oil, and he almost poured engine oil into the transmission—fortunately, I caught it in time. Always referring to the maintenance manual is the way to go; using the right oil ensures the car runs smoothly and reliably.
