Can You Mix Gear Oil With Engine Oil? Get The Facts!

We can all agree that different oil comes with different functions. While some oils can easily be mixed with other oils, some can’t. It’s safe to say that gear oil and engine oil are two different oil in the automobile industry. At times you’ll have people wondering if it is safe to mix both oils.

Before going ahead and mixing these two oils, you’ll first need to know more about the chemical composition of gear and engine oil before mixing them. In this article, we are going to explain everything you need to know about mixing gear oil and engine oil.

Can You Mix Gear Oil With Engine Oil?

As mentioned above, before mixing any two oils you’ll have to first take a look at the chemical composition of both oils just to be on the safe side. However, after properly checking the composition of both oils, then you’ll take into consideration the advantages and disadvantages and make the right decision after.

Chemical Composition and Usage: Gear Oil

It is said that gear oils are made of mainly two components which include the base oils and additives. Gear oil is widely known to be thicket and has a high viscosity when compared to engine oil.

The main purpose of this oil is to effectively gear the car. It is also designed for lubricant gear. The heating oil does a wonderful job of cooling down the gearbox and preventing any form of rust from taking place.

Chemical Composition and Usage: Engine Oil

When compared to gear oil, engine oil on the other hand is equipped with a high amount of base oil and a small number of additives. It is known to have a lot less viscosity than gear oil.

Using engine oil will definitely help the vehicle to perform as best as possible. It also plays a role in protecting the engine from rust and debris. When using engine oil your vehicle run smoothly and all of its parts will be properly lubricated.

What Happens When You Mix Gear Oil With Engine Oil?

Can You Mix Gear Oil With Engine Oil

Mixing gear oil and engine oil together is a bad thing to do since it can lead to your vehicle being wrecked. This is why we think it is not a good idea to mix both of these oils especially if you want to prevent anything bad from happening to your car.

It’s best to keep in mind that mixing gear oil and engine oil can damage the engine and gearbox costing lots of money for repairs. However, we think it is safe for you to add a small amount of lubricant with a large amount of engine oil as this shouldn’t cause any issues.

The thing is that when lubricant is in a lower amount and the oil that is being added is high in viscosity, you can add without having to worry about anything bad happening.

Is It Ok to Mix Gear Oil With Engine Oil?

Some experts suggest that it is a bad idea to mix both oils together. Even though the aim is to add a small amount of gear oil to the engine oil to avoid damage from occurring, it is still not recommended.

Let’s not forget that gear oil comes equipped with more viscosity when compared to engine oils, and if they are mixed, the viscosity will resultant oil changes. So, if it’s a case where you decide to use the resultant oil on your gearbox, either the gearbox or the engine oil pump may damage, which will eventually cost you to repair.

Is Gear Oil the Same as Engine Oil?

There are people out there that actually thinks that gear oil and motor oil are the same but it is not. The thing is that gear oil is designed in a way that allows it to protect and cool the gear system. Motor oil is known to play a role in protecting your vehicle’s engine as well as the engine from gasoline and additives.

Let’s not forget that chemical components tend to have their differences. Gear oil is said to have higher viscosity when compared to motor oil.

FAQS – Frequently Asked Questions

Q. What happens if I put gear oil in my engine?

If somehow you’ve managed to pour a large amount of gear oil into your engine, it will cause it to damage. It ruins the internal parts over time causing the engine not to perform well. However, if you’ve just mixed a small amount of gear oil on the engine that might be safe.

Q. Is gearbox oil the same as engine oil?

The truth is that gearbox oil and engine oil have lots of differences. There is no doubt that you will get some core and visible differences between both oils. As you already know, engine oil is capable of protecting the engine from rust and wear. While gearbox oil is designed to cool the gearbox system allowing it to run smoothly.


It’s never a good idea to mix two lubricants. The reason for this is because the ingredients in both oils are known to be differents, so you should avoiding mixing them. If it’s a case where you don’t have any choice, then you can go ahead and mix a small amount of gear oil with engine oil just to be on the safe side.