What are the differences between gear oil and engine oil?

[DeDelilah]

Gear oil and engine oil have the following differences: 1. Different working environments: Gear oil is mainly used in manual transmissions, reducers, and differentials; while engine oil is the lifeblood of the engine, primarily used inside the car engine. Comparatively, the working environment of engine oil is more demanding. 2. Different functions: Gear oil is mainly used in gearboxes; engine oil is mainly used in engines. Gear oil is primarily used in gearboxes to lubricate the surfaces of various gears, preventing issues like gear sintering and excessive wear; engine oil performs cleaning, lubrication, cooling, and sealing functions within the engine. 3. Different properties: Gear oil is strongly alkaline; engine oil is weakly alkaline. Gear oil emphasizes protection for gears under high temperatures and is strongly alkaline; engine oil focuses on its low-temperature fluidity, being weakly alkaline, and requires high oxidation resistance to adapt to the high-temperature and high-pressure environment of the engine. 4. Different viscosity grades: Gear oil has higher viscosity than engine oil. Gear meshing is line contact, so gear oil must have extremely high viscosity to form an oil film at the gear meshing points; the lubrication points in the engine are mostly surface contact, requiring lower viscosity standards.

[Easton]

Having driven for over a decade, I can clearly distinguish between gear oil and engine oil. Gear oil is used in transmission systems and rear axle gear components, primarily responsible for lubricating gears, preventing wear, and ensuring smooth gear shifting. Engine oil circulates inside the engine to lubricate pistons, crankshafts, and other components, maintaining smooth engine operation. Gear oil typically has higher viscosity because gears endure greater pressure and require thicker lubrication for wear resistance, whereas engine oil is relatively thinner to facilitate flow under high temperatures. Their replacement intervals also differ: engine oil should be changed every 5,000 to 10,000 kilometers, while gear oil may only need replacement every 40,000 to 60,000 kilometers. Using the wrong oil can cause serious damage – gear oil that's too thin may lead to transmission overheating, while neglected engine oil changes can result in carbon buildup or even cylinder seizure. I recommend car owners regularly check fluid conditions, consult their vehicle manuals for correct oil specifications, and avoid costly repairs by cutting corners on maintenance.

[DiAdeline]

As a DIY car enthusiast, I find the difference between gear oil and engine oil particularly crucial when working on my vehicle. Gear oil is specifically designed for transmissions and differentials, lubricating those tough gears with its honey-like high viscosity, requiring a specialized pump for refilling. Engine oil, the lifeblood of the engine, has better fluidity and is simpler to change. The key distinction lies in their additive compositions: gear oil contains anti-wear agents to withstand high-pressure impacts, while engine oil includes detergents to prevent carbon buildup. When changing oils yourself, don't mix them up - otherwise, your transmission might start grinding, and your engine could smoke. In terms of replacement frequency, I change engine oil every six months, whereas gear oil only gets replaced every two to three years. The tools differ too: gear oil changes require funnels and gloves to avoid oil stains. I recommend beginners start with engine oil to gain experience before tackling gear oil.

[OEvangeline]

From the perspective of oil composition, gear oil and engine oil differ significantly. Gear oil has higher viscosity, such as SAE 75W-90 grade, designed for transmission gears to withstand high pressure, hence it contains extreme pressure additives. Engine oil has lower viscosity, like 5W-30, used in engines, with dispersants to maintain internal cleanliness. Functionally, gear oil protects gears to reduce wear, while engine oil lubricates engine components and dissipates heat. In terms of replacement intervals, engine oil requires more frequent changes, typically every 5,000 kilometers, whereas gear oil lasts longer, often over 40,000 kilometers. Using the wrong oil can cause problems: gear oil that's too thin may lead to gear damage, and not changing engine oil can result in engine failure. Simply put, choosing the right oil depends on the vehicle type, with different requirements for manual or automatic transmissions.