
Manual transmissions cannot use automatic transmission fluid for the following reasons: The viscosity of manual transmission fluid is higher than that of automatic transmission fluid, which helps to better lubricate the friction surfaces of manual transmission gears. The fluidity of automatic transmission fluid is higher than that of manual transmission fluid, allowing for faster and more stable transmission of engine power. The heat dissipation capability of automatic transmission fluid is superior to that of manual transmission fluid, preventing excessive temperatures that could reduce lubrication effectiveness and damage moving parts of the automatic transmission, such as causing component jamming, clutch slippage, or seal leakage. The methods for changing transmission fluid are as follows: Loosen the drain screw at the bottom of the transmission to drain the old fluid before refilling. Remove the transmission oil pan directly to drain and refill the fluid: This method is more thorough than the previous one, as it allows for the removal of impurities at the bottom of the oil pan. Use a circulation machine to change automatic transmission fluid: A smart circulation machine can perform dynamic fluid changes, filtering and cleaning sludge and impurities inside the automatic transmission.

I've been in the mechanical industry for over a decade, and manual transmission fluid is completely different from automatic transmission fluid. Manual fluid mainly lubricates gears and synchronizers, with a simple formula and low viscosity; automatic fluid contains additional friction modifiers, making it suitable for clutch plates. If you mix them up, the synchronizer might slip, leading to difficult shifting, loud noises, and long-term damage to the transmission. When servicing your car, always refer to the manual to choose the correct fluid—manual fluids are commonly GL-4 or 75W-90. Regularly checking the fluid level and quality can save you from major repairs. Proper maintenance can significantly extend your vehicle's lifespan and avoid unnecessary replacements.

I was chatting with a friend who almost made a big mistake—thinking automatic transmission fluid was superior and pouring it directly into his manual car. After hitting the road, the gears clunked loudly, the shifts were jerky, and the whole driving experience was uncomfortable. Later, the mechanic explained that the formulations of the two fluids are vastly different, and the additives in automatic fluid can accelerate wear on the manual transmission's synchronizers. Always check the owner's manual before maintenance—don't cut corners by using the wrong product, or minor issues can turn into major problems. Taking care of your car is like wearing well-fitted clothes—get the sizing right, and everything runs smoothly.

As a budget-conscious person, I value getting my money's worth. Automatic transmission fluid is usually more expensive, but it's not suitable for manual cars – the friction modifiers in the oil can actually accelerate component wear, and repairing a transmission can cost thousands. Buying manual-specific oil directly is more affordable and protects the synchronizers. Remember: Saving small amounts isn't worth risking major damage; maintaining your vehicle well offers the best value.


