Every fluid or oil plays an important role in the car’s overall running, be it motor oil, transmission fluid, gear oil, etc. They are equally important for one or the other purpose and ensure a smooth run. Whether you can use one oil for another depends on various factors, and before using one oil in place of another, you must check the effects.

In this article, we will talk about motor oil and transmission fluid. If you wonder, can I use motor oil for transmission fluid, read the article carefully. Let’s get started!

Also Read: Can You Use Vegetable Oil For Engine Oil?

Can I Use Motor Oil For Transmission Fluid?

No, you can’t and you should not use motor oil instead of transmission fluid! Using any oil except for the purpose it is designed can harm your car and lower its performance. Nonetheless, some oils or fluids can be used interchangeably with others. There are a lot of other things u can use instead of power steering fluid but motor oil is not one of them.

Whether motor oil can be used for transmission fluid depends on various factors. Before proceeding forward, let’s first look at the composition of both of them.

What Is Motor Oil Made Of?

Motor oil is a petroleum-based oil containing over 75% of the base oil and other additives important for lubrication. Motor oil is of three types: synthetic oil, non-synthetic oil, and mineral oil, and all of them contain some proportions of petroleum, whether crude or refined. 

Also Read: Can You Mix Gear Oil With Engine Oil?

Motor oil is majorly used for the lubrication of parts inside the engine, and this is why there are several additives present in the motor oil that makes it a good lubricant. Apart from lubricants, other additives like detergents, anti-wear and tear, viscosity-related additives, antifreeze additives are also present that helps in enhancing the quality of motor oil.

What Is Transmission Fluid Made Of?

Transmission fluid these days is of two types, Automatic Transmission Fluid(ATF) and Manual Transmission Fluid, but both are almost similar in composition. Transmission fluids contain crude oil and easter as base oil, and like motor oil, they also contain additives.

Manual Transmission fluids are much heavier than automatic transmission fluids. Both play a major role in ensuring the smooth shifting of gears. Transmission fluid also helps lubricate and cool down the parts inside the gearbox or gear system and prevents wear. 

From the above, it is clear that both have one role in common: the lubrication of parts, but even after this, you cannot use motor oil for transmission fluid.

Let us look at the differences between them based on various factors.

Difference Between Motor Oil And Transmission Fluid!

FactorsMotor OilTransmission Fluid
CompositionComposed of over 75% base oil. Motor oil is petroleum and hydrocarbon-based. It also contains several additives.Transmission fluid contains crude oil and ester as base oil, and this also contains a few additives.
TypesMajorly Of Three Types: Mineral Motor OilSynthetic Motor OilSemi-Synthetic Motor OilThis Is Of Two Types: Manual Transmission FluidAutomatic Transmission Fluid(ATF)
ViscosityAt operational or running temperature, motor oil has an approximate viscosity of 10 centistokes, but this also depends on the type.At operating temperature, transmission fluid usually has an approximate viscosity of 7.5 centistokes, which also depends on the type of transmission fluid used.
UsesMotor oil is for engines. Its main uses include lubricating parts inside the engine, protecting the parts from wear and breakdown due to excessive heat, cooling down the parts, etc.Transmission fluid is for the transmission system or gearbox. Its main uses include lubrication of parts, a frictionless or smooth shift of gear, protection from breakdown or failure of the gearbox, and in the case of ATF, it also plays a major role in providing pressure for the automatic shift of gear.

After looking at the composition of motor oil and transmission fluid and the differences between them, we have a fair understanding of both of them, and now comes the turn to see why you should not use motor oil for transmission fluid. 

Also Read: What Can I Use Instead Of Power Steering Fluid

Why Should I Not Use Motor Oil For Transmission Fluid?

Using motor oil for transmission fluid is indeed a bad idea. As mentioned above, although they have one use in common, the lubrication of parts, both of them have different compositions. That is why using motor oil for transmission fluid might not be a safe option due to some additives.

Motor oil has a slightly higher viscosity than fluid on operating temperature or while the car is in motion, which means it is slightly thick than transmission fluid. If this is used for transmission fluid, it might cause low performance in shifting of gear, and you might start hearing some weird sounds coming from the bearings due to lack of lubrication. 

Using motor oil for transmission fluids can also cause the gear to slip. Especially in the case of ATF, the gear system might break down as motor oil won’t provide the appropriate pressure required for the automatic shift of gears. 

In worst cases, there might be a possibility that the car does not function well when on gear, and this can lead to various dangerous situations, so you should avoid using motor oil for transmission fluid.


Using motor oil for transmission fluid is not recommended as both are designed for specific purposes. Motor oil can damage the transmission system and cause low performance and problems in shifting gear both in the manual and automatic systems if used for transmission fluid. So the answer to your question is no, you cannot use motor oil for transmission fluid.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *