Can I use Motor Oil for Transmission Fluid?

Often, people have this misconception about substituting motor oil for transmission fluid.  Yes! Both Fluids are similar. They are important for seamless vehicle performance but are designed to function uniquely. So you may ask. Can I use motor oil for transmission fluid?

The answer is NO. Using it will damage your vehicle’s transmission. Motor oil works for your engine while transmission fluids take care of your transmission.  However, to help you understand better, let’s take a look at some basics.

Motor Oil

Motor oil is a combination of several bases and additives that serve as a lubricant to engine parts, keeping the engine clean, cool, and protected.

Transmission Fluid

Transmission fluid is a fluid used to lubricate parts of a car’s transmission for excellent performance. It also allows easy engagement of your clutches and gears.

The reason I explained both fluids is because most people often confuse both for each other. In fact, some have used it before. However, ask yourself this simple question. If both fluids have the same functions, why will different compartments be made for them? Yes, you heard that right. I will explain as we proceed. But, let’s look at their differences.

Differences Between Motor Oil And Transmission Fluid Explained

First, your motor oil is made for your engine. It helps to handle anything that has to do with combustion. It works to tighten and prevent corrosion on different engine parts, remove thick debris on engine parts, keep the engine system cool and lower the friction between movable components in your engine. While the transmission fluid helps your auto and manual transmission to function properly.

Furthermore, while motor oil contains contaminants that must be drained after a short period or after covering a particular mileage. Transmission fluids are used in a closed compartment, which makes them last for a longer time. So you do not need to change it often.

The main difference between both fluids is that motor oil works directly with your engine area to deal with combustion. While the transmission fluid functions to lubricate the transmission system of your car, allowing easy engagement of your clutches and gears. Your steering system also uses transmission fluid to keep its components running seamlessly.

Related topic: is motorcraft oil good

Motor Oil and Transmission Fluid Compared

This comparison details how to tell the difference between transmission fluid and oil. Thus helping you understand the answer to the question above.

  1. Function: Motor oil functions to tighten engine parts, keep the engine cool, protect the engine from rust, eliminate thick grease from the engine parts,  and lubricate the mobile part of the vehicle engine. While the transmission fluid is used on your car’s transmission to ensure the seamless performance of your clutches, gear, and steering system.
  2. Consumption rate: Motor oil reduces as you drive, so it is advisable to check your oil after covering a certain distance. While transmission fluid does not reduce with time. However, there are cases where you might have a low level of transmission fluid.
  3. Colour: Motor oil color comes freshly as golden brown or bright yellow, but turns black after being used for some time. While transmission fluid is red.
  4. Life Span: Motor oil lasts for a short time because you will need to change it after covering about 3000-6000 miles. While transmission fluid lasts for a long time, so you do not need to change it regularly.
  5. Detergents: Motor oil has a small amount of detergent. While Transmission fluid has a high concentration of detergent which helps to keep transmission clean.
  6. Viscosity: Motor oil operates under high temperature while transmission fluid functions under low temperature or pressure.
atf as an engine oil substitute

Can I use Motor Oil for Transmission Fluid?

Both fluids have distinct similarities, People substituted them in the past. Some believe that a small amount of motor oil in transmission will not cause much harm if you flush your trans after driving your car. (This is serious work).

But can I use motor oil for transmission fluid? The answer is no. Motor oil does not have the right friction modifiers and additives to function in the transmission. Using it might damage your vehicle,  causing you to experience any of the following problems:

Grinding Sensation in Gear

Motor oil in your transmission can cause a mismatch in your wheels and engine. In other words, the speed of your engine and wheels might not function uniformly.

Vehicle Unable to Function while in Gear

The wrong oil in your transmission will make it very difficult for vehicles to go into gear. That is, unable to transfer power from the engine to the wheel.

Gurgling Noise And Transmission Fluid Leak

A car when under motion, can make certain noises which you will know as a driver. But when your car starts making an unfamiliar and scary noise, it means trouble may lie ahead. Among other things, this may be because of the wrong oil in your transmission. A mismatch in your wheel and engine is likely to cause this noise.

Burning Smells

Motor oil in your trans can make your vehicle have a burning smell. This may happen because of fluid overheating. However, transmission fluid has higher lubricating properties that help prevent any damage that happens in the transmission parts. 

Gear Slipping

The wrong fluid in your transmission will cause your gear to shift unnecessarily while driving. Making your car slow down suddenly. 

Engine Checks light turn on

Having the wrong oil in your transmission may cause your engine’s check light to turn on often.

Fixing Problems Caused By Motor Oil on Transmission Fluid

When you start seeing any of the above problems in your vehicle or anything unusual. You can fix it by following the steps below. However, this may depend on the degree of damage or how long the motor oil has been in your car’s transmission.

  • Flush your transmission
  • Refill Your transmission
  • Make sure you use the right fluid that tally with your car’s technology (check your owners’ manual)
  • If you have done the above, yet you still experience these problems, you may need to see a mechanic.

Frequently Asked Questions

Can I Use Motor Oil For Transmission Fluid?

No, you should not use it. Both fluids might be similar. People of old may have substituted it. But to avoid any car damage and to be on the safe side, it is best to use only transmission fluid for your transmission. If they can be substituted without effect, different compartments would not have been made for motor oil and transmission fluid.

What Happens If I Use Motor Oil For Transmission?

Using Motor Oil for transmission might cause your vehicle to develop certain problems. And if not noticed on time, your vehicle might break down severely, causing you to spend unnecessarily.

Can ATF last a lifetime?

No, ATF cannot last a lifetime. However, your automatic transmission fluid can be used for a long time without changing it.

Will any Transmission Fluid work?

Any transmission fluid may work but may eventually damage your transmission. This is because a specific transmission fluid is supposed to be used for certain cars. So we advise that you check your car owner’s manual to determine which fluid best suits your car’s transmission.

Can You Put Marvel Mystery Oil in Transmission?

Yes, you can put marvel mystery oil in your transmission. It is safe to use because it increases gas mileage, reduces engine wear, cleanses clogged engines, and enhances overall performance. However, do not use more than 16 ounces of marvel mystery oil at a time.

Final Thought

You may substitute motor oil for your trans and not see an instant problem. But time shall tell. Note that every car’s transmission (manual or automatic) has recommended transmission fluid. So not using an exact fluid for a particular car may cause problems, let alone using something entirely different.

With these explained, you may still want to ask. Can I use motor oil for transmission fluid? No, do not. Both fluids function differently, so use each for its purpose to avoid unnecessary car issues.

Leave a Comment