Can You Mix 10w30 and 10w40 Oil? (Explained!)

Many car drivers have already been mixing 10w30 and 10w40 oil, and they reported no damage at all for their vehicles and their engines. However, many car drivers are hesitant to do it because they are afraid of the consequences that the mixing can do. So now, we are going to talk about this matter.

So can you mix 10w30 and 10w40 oil? The answer is yes; you can mix 10w30 and 10w40 oil. However, just because you can mix it, it does not mean that you have to. It is not recommended.

As mentioned, a lot of car drivers are already doing the mixing of both these oils. Many have reported that they have not experienced any harm or harmful effects that the mixture did for their engines and vehicles. That is why a lot of car drivers are already following the activity and doing the same. 

But on the other hand, many car drivers are also on the other side of the room because they believe that doing such a thing can cause harm to the engine and the vehicle. If you are curious about it also, then this article is definitely for you. In this article, we are going to discuss if you can mix 10w30 and 10w40 oil. 

We will also discuss what happens if you mix both of these oils. If you have the same questions and are curious about this matter, stay for a very informative read. So without further ado, let us start.

Can You Mix 10w30 and 10w40 Oil

Can I Mix 10w30 and 10w40 Oil?

Yes, you can mix 10w30 and 10w40 oil. However, it is essential to know that this act is not recommended. This act is advised not to do. 

But if you have no other choice, then you can mix 10w30 and 10w40 oil. You have to make sure that both of them have the same brand, and you also have to make sure that both of these oils have the same manufacturers. This ensures that both of them contain the same set of additives, thus making them compatible. 

You also need to check if the vehicle’s engine is compatible to work for both the 10w30 and 10w40 oil. In engines that are high performance, the 10w40 can be too thick. Most of the engines made today are using lighter oil. This is to save on fuel economy. 

If you search the internet or ask everybody about this question, you will receive a lot of different answers. Some car drivers would say that it is okay, and some car drivers would also say it is not okay. But in reality, this is not encouraged, and it is advised not to do it. 

If you mix 10w30 and 10w40 oil, the oil pressure will tend to decrease on engine higher revs.  You can also have a bad bearing or two.

Can You Add 10w30 to 10w40 Oil?

Yes, you can add 10w30 to 10w40 oil. Many car drivers have already been doing this. You might also experience this. You may need to top up your current oil, and there is no available oil that is the same as your current oil. 

With that, you will need to add them up. With that, it is okay, but it is not recommended. If you have no other choice, you can do the top-up and not worry about any damage or engine failure. 

Make sure also that both of the oils have the same additives. That means you have to make sure that both of the oils have the same brand.

Can You Add 10w40 to 10w30 Oil?

Yes, you can also add 10w40 to 10w30 oil. You will come to a situation where you will not have a choice; you will have to do the top-up. 

You also have to make sure that both of the oils have the same brand. The same brand means the same additives on the oil. This is for the compatibility of the oils.

Is It Ok To Mix 10w30 and 10w40 – Possible Downsides?

Well, this question gets a lot of different answers. If you ask the public, they will each have their answers. Some people will say that it is okay. 

Some people will also say that it is not okay. You might be confused as to whom you should believe and follow. Some car drivers will tell you that mixing both of these oils is okay if you do not live in cold-weather places. 

But even if you mix both of these oils, you do not have to worry about severe damage to your engine and vehicle. The damage is pretty unlikely. Some people would also say that it is okay to mix them if you only mix a little bit of the other oil. 

But a lot of car drivers and mechanics are still avoiding mixing both of these oils. Some car drivers are afraid that if they mix up two oils, they will decrease the oil pressure when they are cornering at high revs. This can then result in the spinning of a bearing or even two bearings. 

You should also know about the possible downside of this mixing. If you use a mixture of two oils, then it might affect the warranty of your vehicle. It can also affect your fuel consumption. 

In cold startups, both of the oils will function just the same. So if you find yourself in an emergency, then you can do the mixing. But you have to remember that you have to avoid mixing them up if you can.

What Happens if You Mix 10w30 and 10w40 Oil?

If you mix 10w40 to 10w30 oil, nothing serious will happen, though. Those car drivers who are already doing it have reported no signs of damage or any changes to their vehicle. 

However, it does not mean that you should always do this and make it a habit. You need to avoid this activity. You can also lose the warranty of your vehicle for this mixing.

Summary

In summary, many car drivers are asking if they can mix 10w40 to 10w30 oil. Many car drivers will say yes and are already doing it for a long time. Other car drivers oppose the idea. 

But there can be no harm in mixing both of these oils. You can risk your vehicle’s warranty. However, there is no severe damage that can happen to your car.

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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