Is Oil and Transmission Fluid the Same: Know Now!
There are varieties of oils, and it is quite common for people to get confused about them. Last week, one of my friends came to me and asked, “Is oil and transmission fluid the same?” He wanted to use one for the other. Well, I clearly had to forbid him.
Oil and transmission fluid are far from being the same. Engine oils are lubricants that increase the engine’s performance and help with overall fuel efficiency. On the other hand, transmission fluids are known as hydraulic oil, which helps provide power in the car’s transmission.
In the article below, I have discussed the characteristics of engine oil and transmission fluid, along with their differences. Have a good look.

What is Engine Oil
Engine oils are automotive lubricants that help to enhance the engine’s performance. Good oils help with fuel economy and efficiency.
Engine oils usually come in three varieties-
- Conventional
- Synthetic
- Semi-Synthetic
These oils serve different purposes compared to transmission fluids.
Engine oils help to keep the engine clean alongside ensuring it’s overall best performance. They lubricate all the components in the engine.
What else? Well, they contain different types of additives in them. It helps to provide protection against engine wear and corrosion.
They are formulated in a way that helps to keep the engine cool.
If you use the perfect engine oil you will be able to make sure that the vehicle’s engine gets a proper lifespan. Not just that, Engine oils also boost engine sealing as well.
To summarize, engine oils lubricants and helps all the components of the engines to perform properly.
That’s why you should always try to get the best possible oil for the vehicle’s engine. It will confirm good fuel efficiency and help to keep the engine in good shape.
What is Transmission Fluid
Transmission fluid is one type of hydraulic fluid which helps to lubricate the components of the car’s transmission. It simply transfers power to the transmission from the engine.
Transmission fluid can be mainly of two types-
- Automatic Transmission Fluid
- Manual Transmission Fluid
Wondering what these two do and how they differ?
It is just like their name goes. An automatic transmission fluid is used for a vehicle which has a fully automatic transmission system.
On the other hand, when there is manual gearbox equipment, manual transmission fluid is mostly used.
The main purpose of these transmission fluids is to make sure that the entire transmission system of the vehicle functions properly. But it’s just not that. You will be amazed to learn what else these fluids can do.
They can control the heat resistance of the vehicle’s transmission system. So, these fluids can act as a coolant and help the engine to cool down.
Of course, the robust cooling system does the main job, but the transmission fluid can be really helpful too.
While reaching their desired destination, they clean their way out. The hydraulic fluids remove different types of contaminants from the hydraulic system.
Also, just like engine oil, they help to prevent corrosion as well.
See? These fluids come with a lot of offerings. And they are really helpful for the transmission system. But what separates them from oil? Find it in the following section.
Oil vs Transmission Fluid: 5 Key Differences
Here, I have discussed the major differences between engine and transmission fluid. Give it a read from top to bottom, and you’ll understand why oil and transmission fluid are not the same.
Parameters | Engine Oil | Transmission Fluid |
Function | Engine | Transmission System |
Lifespan | Shorter | Longer |
Temperature | High | Low |
Viscosity | Low | High |
Color | Amber | Red |
Periodic Cleaning | Required | Not Required |
1. Function
This is the main difference that separates the two. While engine oil is designed to function in the engines, transmission fluid mainly operates in the transmission system.
Engine oil designed to boost your engine’s performance. It ensures the engine’s longevity and the fuel efficiency.
These oils lubricate the important components of the engine and make sure the engine keeps running at its best. It also removes different kinds of friction and clears the engine from different forms of sludge.
On the other hand, Transmission fluid is designed to work in the transmission system. It shifts power from the engine to the transmission system.
It ensures that the hydraulic parts of the vehicle function properly.
These fluids help in the performance of the gears and clutches of the transmission system. They make sure that the gear system communicates properly.
2. Lifespan
Engine oils have a shorter lifespan compared to transmission fluid.
Engine oil loses its effectiveness over time and mileage. My recommendation would be that you change your engine oil every 3000-6000 miles.
Though it depends a lot on what type of oil you are using. But if you don’t change it and keep on using it for a long period, it will surely harm the engine.
But transmission fluid has a really long lifespan. You don’t need to change it that often.
If you are using MTF (manual transmission fluid), then I would recommend that you change it every 30000 to 60000 miles.
But if you use ATF (automatic transmission fluid), then you can use it for even longer. These fluids last for 60000–100000 miles.
No matter which one you are using, it needs proper maintenance. So make sure that they are changed when they reach out of their running range.
3. Temperature
Engine Oils usually work at higher temperature levels than transmission fluids.
Transmission fluids have an operating temperature of 347° Fahrenheit (175° Celsius) to 428° Fahrenheit (220° Celsius).
But, engine oils operate on a higher temperature level. Their operating temperature level is usually between 446° Fahrenheit (230° Celsius) to 500° Fahrenheit(230° Celsius).
4. Viscosity
Now let’s come to the next parameter.
Viscosity plays a major part for the components of the vehicle. And the viscosity level of engine oil is usually lower than the transmission fluids.
5. Color
Transmission fluids and engine oil come in completely different forms of colors.
Engine oils normally have an amber color. I mean you can find it in Golden or bright yellow color as well. But when time goes by, the engine oil might turn black. Don’t forget to replace it after 3000 to 6000 miles.
And, most transmission fluids are usually translucent and red. Totally different from the engine oil. It will turn dark red from time to time.
6. Periodic Cleaning
If you are using engine oil, then replacing it from time to time isn’t the only concern you should have. You need to perform periodic cleaning as well.
Otherwise, it will develop debris around them.
But in the case of transmission fluid, periodic cleaning isn’t required.
Can I Use Engine Oil for the Transmission System?
Well, the straight cut answer is you should not.
It will create problems for the vehicle in the long run. A lot of people do that without knowing the actual outcome.
If you use a lot of engine oil in transmission fluid and drive a vehicle for a long time, then it will surely affect the gearbox.
Also, transmission fluid makes sure that the transmission parts are properly lubricated and the hydraulic parts operate very smoothly.
But if you keep using engine oil, you won’t get the best performance from the transmission system. It will lose its efficiency. Also, you will face the following outcomes-
- Burning smell coming out of the transmission system.
- While driving, you might find gears slipping.
- Grinding sensation coming from the gears.
- You will continuously find the ‘Check Engine’ light on.
- Different kinds of noises from the vehicle.
So, putting a bit of engine oil might not cause you any problem. But if you continuously keep on doing it, it will hamper the components of the gearbox.
Engine oils weren’t made for the transmission system, transmission fluids were. That is why you should not use engine oils in the transmission system. Always try to use good transmission fluids.
Frequently Asked Questions
1. What is the average oil change cost?
Answer: If you use synthetic oils, they will cost you between $65 and $125. But if you use conventional oil, the cost will come down. It will be around $35 to $75. However, check the owner’s manual and use the best type of oil that is suitable for your vehicle.
2. What is the average Transmission Fluid Change Cost?
Answer: A transmission fluid change will cost you between $150 and $175.But for a transmission fluid flush, it will cost you a lot more. It will be around $160 to $300.
3. How to check transmission fluid level?
Answer: You can check the transmission fluid level using the dipstick. However, many cars do not come with a transmission dipstick. You can check here to get a detailed idea about checking the transmission fluid level.
Final Thought
Well, there you go. Is oil and transmission fluid the same? I believe you have your answer.
Engine oils were made for engines and transmission fluids for the gearbox. They each have their own purposes to serve. That is why it is never wise to use one for the other.
Also, try to keep your vehicle well maintained. Till then, take care!