What Types of Manual Transmission Fluid Are There?

[OHaley]

Below is a detailed introduction to manual transmissions: 1. The full name of a manual transmission is 'manual shift transmission,' which, as the name suggests, requires the driver to manually shift gears while using the left foot to operate the clutch to complete the gear change. Because of this, the shifting process in a manual transmission involves 'power output → power interruption (depressing the clutch) → gear change → power output (engaging the clutch).' 2. The transmission efficiency of a manual transmission varies depending on gear design and gear ratios, averaging between 96~98%. Due to its simple structure, manual transmissions are generally lighter and more durable. More importantly, manual transmissions require more attention from the driver and allow for greater control over gear changes, along with many special driving techniques.

[AmeliaFitz]

Having driven manual transmission cars for over a decade, my experience with gear oil changes tells me that manual transmission fluids are primarily API GL-4 grade gear oils, specifically designed for manuals. Unlike GL-5, they don’t contain excessive corrosive additives that could damage synchronizer rings. In terms of viscosity, 75W-90 is common and suitable for year-round use—ensuring smooth cold starts in winter and robust high-temperature protection in summer. Base oils fall into three categories: mineral, full synthetic, and semi-synthetic. Mineral oil is cost-effective but has a shorter lifespan, requiring frequent changes. Full synthetic offers better high-temperature resistance and fluidity; though pricier, it extends transmission life. Remember to inspect or replace it every 30,000 km—neglecting this may lead to rough shifting or even major transmission overhauls.

[VanLillian]

As a car enthusiast who loves researching, I understand that manual transmission fluids have specific types. First is the API standard, with GL-4 being the mainstream choice because its anti-wear properties are moderate, unlike GL-5 which is used for differentials and can easily corrode manual components. In terms of viscosity, 75W-90 is the most commonly used, ensuring smooth gear lubrication in both cold and hot environments. The base oil categories include mineral oil (low cost but prone to oxidation), semi-synthetic oil (a balanced option), and full synthetic oil (high performance, suitable for long-distance driving). Using the wrong fluid can accelerate wear, so it's recommended to choose the oil according to the car manual and change it every 2 years. Proper maintenance can ensure smooth gear shifting.

[VanLeonardo]

I recently researched and found that the common type of manual transmission fluid is GL-4 grade gear oil, with 75W-90 viscosity being the most prevalent, providing stable lubrication. There are three types of base oils: mineral oil is economical but requires frequent changes; synthetic oil offers strong durability and reduces friction; semi-synthetic oil is a balanced choice. It's crucial not to confuse it with GL-5, which is designed for rear axles and unsuitable for manual transmissions. Regular oil changes prevent impurity buildup, with inspections recommended approximately every 30,000 kilometers.