Can You Mix 5w20 and 5w30 Oil? (Explained!)

Engine oil is essential for your vehicle. But many people are asking if they can mix a 5w20 oil and a 5w30 oil. If you wish to know the answer, stay and keep reading.

So can you mix 5w20 and 5w30 oil? Yes, you can mix 5w20 oil with 5w30 oil, but it is not advisable. Though there are no significant problems with this fusion, it is never recommended for any vehicle.

People are divided when it comes to this question. Some people will stick with it being alright if you mix two different viscosity levels of your motor oil. However, some people think that mixing these oils will cause severe damage to your vehicle and its engine. 

But in reality, saying that mixing a 5w20 and 5w30 oil will cause significant problems is over the top. Though mixing both of these oils is not recommended, it does not mean that it would cause significant severe problems like an engine failure. On the contrary, a 5w30 and a 5w30 can offer you and your vehicle the same good performance. 

Both of these oils can flow at low temperatures very evenly. With that, both of these oils will blend perfectly, given that they have the same brand and the same API class. However, there are moments when you would be forced to use a different viscosity level because of the availability of such a product. 

With that, it is essential to know what are the things that you can do and what are the things that you can do when mixing or adding up two oils with different viscosities. So this article is for you to know more about the mixture of 5w20 and 5w30 oil. So without further ado, let us get started.

Can You Mix 5w20 and 5w30 Oil

Can I Mix 5w20 and 5w30 Oil?

The simple answer is yes. Yes, you can mix 5w20 oil with 5w30 oil. If you are thinking about the safety of your vehicle and its engine, do not fret because it will be entirely safe. 

You could be topping your engine oil of 5w20 or 5w30 with each other; you will not cause any serious and significant danger to the components of your engine. This is because engine oils have different additives. The difference between their additives makes them have that difference in their weight rating. 

If you mix these oils, the additives will not blend and become one. However, it also will not cause serious harm to your engine. Some people will ask the critical question of why you would mix both of them. 

Some people might have run out of their original oil to use a different viscosity level. If that is the matter, the best thing to do is drain the original oil in your vehicle and then change the entire oil with a different one. But draining the entire oil or not draining the entire oil will not cause failures to your engine. 

So you can do either of them. To maintain the security of your vehicle, you can even do your research. You can refer to your owner’s manual and check if the activity will cause danger to your vehicle. 

The 5w20 and the 5w30 have the same winter rating. When we say that they have the same winter rating, both will display the same viscosity under cold conditions. 

But you should know that the 5w30 features a slightly higher viscosity at one hundred degrees celsius if you compare it with a 5w20. So for average temperatures, the 5w30 oil will now be thicker than the 5w-20.

Can You Add 5w20 to 5w30 Oil?

Yes, you can add up your 5w20 to 5w30 oil, and it would cause very minimal issues or just changes. It does not even affect your engine, and you will never notice any differences. 

However, it is most safe if both the oils have the same manufacturer and API classification. If you do this because there is no available 5w30 oil, you can just change your entire oil rather than topping it up.

Can You Add 5w30 to 5w20 Oil?

Yes, you can also add 5w30 to your 5w20 oil. But, again, there will be no significant changes worth your attention. 

Some people might recommend not doing it, but modern oil is now, and the viscosity characteristics can be mixed. So you can add these two up if you have no other choice.

Is It Ok To Mix 5w20 and 5w30 – Possible Downsides?

Yes, it is okay. You can mix a 5w20 to a 5w30 oil, and you will encounter no significant or severe issues at all. But, again, you have to ensure that they have the same API classification and are manufactured with the same classification. 

However, if you can avoid mixing the two of them, you probably should. This is because the rule of thumb is always to follow the recommended viscosity, and the recommendation is not to mix two different viscosities. 

If you want to stay on the safe side, then you can follow this rule. However, if you want to be a bit more challenged, you can try the mixture.

What Happens if You Mix 5w20 and 5w30 Oil?

Mixing a 5w20 and 5w30 oil will have nothing serious going on. Both of the oils will just come together. The oil blending into one will not likely happen, though; they might stay on their side and flow separately. 

As mentioned before, you should make sure that these oils you are mixing have the same brand. This is because the differences will not be huge and with that, it can maintain a good performance.


In summary, yes, you can mix a 5w20 oil with a 5w30 oil. Just make sure that they have the same brand. If they do not have the same brand, that is still okay, though. 

Motor oils do not last for a long time, so you need to change them. If you add a different viscosity level to your original oil, it is best to change the entire oil.



Image credits – Canva

Share on:

My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more