Can You Mix 5w30 and 5w40?

Which is better for your engine, between 5w30 and 5w40? First of all, which of these oils was indicated in your car’s manual, and which one is the best for your engine?

Many drivers mix engine oils due to several reasons. Is it possible to mix 5w30 and 5w40 oil? The engine of a car can’t function if it doesn’t have enough oil.

The performance and duration of the oil used for your car engine will be determined by the type of oil you use.

Motor oils are usually formulated to enhance car engine performance and improve fuel efficiency; however, when mixed, this purpose is somehow diminished.


Is It Possible To Mix 5w30 And 5w40 Oil?

It would make you understand our conclusion and answer the question if you explained the difference between the two oils.

The viscosity and weight of the oil are represented by the numbers before and after the letter “W”, which is the winter season.

The number after the letter is the weight and the number before the letter is the viscosity rating.

For 5W30 and 5W40, it means that both oils will flow evenly at low temperatures because they both have a low viscosity rating of “5.

Now that you know the differences, it is time to mix them. It is not a bad idea to mix two oils of different weights.

Your engine won’t get the full benefits it was supposed to get from the oils you mixed, that’s the only practical CON.

If your engine has been running with 5W30, upgrading to 5W40 won’t be any worse, and downgrading from 5W40 to 5W30 won’t bother you.

What Will Happen When You Mix 5w30 And 5w40 Oil?

The oils have different weights so they will not mix.

5W40 is meant for higher temperatures, but it will not deliver its full potential to your car engine because it is mixed with another oil.

It is good for fuel economy that both 5W30 and 5W40 will flow evenly at low temp.

When you mix these oils, your engine will not enjoy the full potential of both oils that have been mixed.

It’s important to know that mixing oils can reduce the gap between oil changes; you may now have to change the oil more frequently than before.

If you mix 5W30 and 5W40 from the same brand or different brands, all that has been shared in this article still applies.

If you mix oils from the same brand, the oils will have a better chance of delivering the best results.

Difference Between 5w-30 and 5w-40

There are different types of engine oils available for purchase.

When you are presented with so many options, it can be difficult to decide, especially if you don’t know the difference between engine oils.

If there are any differences between 5w30 and 5w40, what are they? 5W-40 is ideal for use in warmer climates because of its superior performance at higher temperatures.

You can break down their names to find out more about their properties. Both of them start with the number 5 and have the same middle name.

We will get to more of that later, but we want to focus on the last number in their names.

When oil is heated to a high temperature, the last numbers in 5W-40 and 5W-30 are 30 and 40.

You need to make sure that the engine oil you use is the correct one. The performance will be harmed if your engine oil is too sticky.

It will harm performance if your engine oil is too dense. Engine oil with low Viscosity will facilitate performance while failing to protect moving parts in the engine.

Which Is Better for Winter?

Now that you know the differences between 5W-40 and 5W-30 engine oil, it’s time to figure out when you should use each type.

We already know that 5W-40 is better for the summer in hot climates, so should you use 5W-30 during the cold winter months?

The “5W” at the beginning of their names means that they are winter-suited engine oils and have the same viscosity at low temperatures.

The cold-weather viscosity of the engine oils is relatively low. The number before the word Winter refers to how well it will flow during the winter.

A low number is a sign that it flows better. When it starts at 5, the engine oil will perform well, but when it starts at 10 or 15, it won’t.

The Society of automotive engineers came up with the names for the engine oils.

The first number indicates the performance at low temperatures, and the last number indicates the performance at high temperatures in the name of the oil.

The climate has an effect on which engine oil is best for your car.



Is it possible to mix 5W30 and 5W40 oil? You can mix the oils, they have the same low temp viscosity rating and would flow evenly to the top ends.

Because of the difference in weight, the oils won’t mix properly. This does not pose a problem to your engine. Synthetic oils can be mixed with semi-synthetics or even high-mileage oils.

It is not possible to improve the performance of your engine if you mix different oils.

If you follow the instructions in the manual, you can keep up with the recommended oil for your engine.

Since oil blends or mixed oils don’t promise any good advantages, there’s no need to practice such acts. You may void your car’s warranty coverage.

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