Can Gear Oil Be Used as a Substitute for Engine Oil?

[DelAlexa]

Gear oil cannot be used as a substitute for engine oil, as it can lead to various faults in the combustion chamber. Below are the reasons why gear oil cannot replace engine oil and additional information: When gear oil is used as a substitute for engine oil and mixes with fuel gasoline to enter the combustion chamber, the fuel evaporates and burns, while some of the gear oil burns along with it. If gear oil is used in place of engine oil, due to its higher viscosity and different composition compared to specialized engine oil, it tends to form deposits in the combustion chamber, leading to issues like spark plug carbon bridging and ignition failure. Additionally, the extreme pressure properties of gear oil are too strong, which can cause corrosive wear. Automotive gear oil is designed for gear transmission components such as transmissions, steering gears, and reducers, serving a lubrication function. It helps reduce wear on gears and other moving parts, extending their lifespan; decreases friction and power loss; disperses heat, providing a certain cooling effect; prevents corrosion and rust; reduces operational noise and minimizes vibration and impact between gears. It also helps flush away contaminants, especially those on gear surfaces, thereby reducing wear.

[DiPaul]

Gear oil really can't replace engine oil, and I learned this the hard way. During a test drive last time, I thought the two oils were similar, but after adding gear oil, the engine started making rattling noises. Later, I found out that gear oil has too high viscosity, which can easily form sludge and clog oil passages. Engine oil, on the other hand, is specifically designed for the high temperatures and pressures of an engine, capable of withstanding the heat and contaminants from the combustion chamber. Mixing them can lead to lubrication failure, accelerated cylinder wall wear, or even cylinder scuffing, causing repair costs to skyrocket. It's advisable to always choose the correct oil grade, such as SAE 5W-30, and avoid shortcuts that could ruin the engine. Regularly checking oil levels and color is also crucial; developing this habit ensures your car runs longer and smoother.

[LaOscar]

I used to think gear oil and engine oil were pretty much the same, and thought I could save some money by mixing them. But soon, the engine started overheating, and fuel consumption skyrocketed. Upon disassembly, I found it full of black deposits. It turns out the additives and viscosity of gear oil aren't suitable for the low-speed, high-torque conditions of an engine, easily causing unstable oil pressure. This mistake cost me over 800 to repair the piston rings. Now, I stick to using proper engine oil, selecting the right type according to the vehicle manual, to avoid penny-wise and pound-foolish decisions that could affect engine longevity. Remember, different oils serve different purposes—vehicle maintenance requires careful attention.

[VonGabriel]

Using gear oil as a substitute for engine oil may seem cost-effective on the surface, but it poses significant risks in the long run. Engines require oil with specific viscosity and cleaning properties to handle high-speed operation and thermal loads, while gear oil focuses more on wear resistance but has higher thickness. Swapping them can lead to oil film rupture, increased component friction, and reduced fuel efficiency. In severe cases, it may necessitate engine replacement or major repairs, costing far more than the savings on oil. I've heard numerous similar cases from repair shops where a single misuse triggered a chain of problems. The correct approach is to select the appropriate engine oil as per the manual and maintain regular oil changes for better cost-efficiency.