Can I Mix 5w30 With 10w30? – The Ultimate Lubricant Guide!

Automobile owners spend thousands of dollars each year just to keep their cars running. However, spending money isn’t the only thing that is required. You should also know about engine specs and lubricant requirements. If you are an automobile fanatic, you have thought of the question, “can I mix 5w30 with 10w30?

Well, this mixture is indeed possible, but that doesn’t mean that it is ideal. These oils have different viscosity and flow at different rates. While it is rare, your car engine could get damaged depending on the difference in viscosity. That is why most automobile fanatics use special additives to encourage conventional oil blending in these cases. 

So are you interested yet? In this article, we will be talking about everything you must know when mixing 5w30 oil with 10w30 oil. So scroll down and keep reading. You will get all your answers soon!

Can I Mix 5w30 with 10w30? (Explained)     

Can I mix 5w30 with 10w30? Well, many drivers often think it is good to pour 5w30 oil with 10w30 oil. This combination is indeed safe. It isn’t corrosive, nor will it catch flames or react with each other. Since they have the same carbon number, they are inert in each other’s presence.

To prove this, many drivers have experimented. Some drivers used 10w30 in an engine that used 5w30, while the others did vice versa. Nothing happened that could prove to be fatal. There were no explosions, nor did the engine show any malfunctions. This mixture was perfect for use. 

However, several flaws were also found when the experiment was over. To start things off with, the oil mixture wasn’t efficient. 

Let us consider the engines that used 5w30 oil previously. The machine had already adapted to the 5w30 oils operating temperature. However, 10w30 oil has a different operating temperature due to the different viscosity grades. Therefore the mixture will not operate together. 

When the 5w30 engine oil has been burnt off, the 10w30 oil will operate. There is a gap in the temperature between the two, and the engine requires a little more energy to reach that temperature. Therefore the energy consumption increases, thus reducing the overall efficiency.      

Additionally, the engines were also affected up to a certain extent. While they had the same carbon numbers, the density of the oils was different. Therefore its viscosity deviates from each other, although it is not significant. This results in a greater carbon emission than when the engine used the oil separately.

What happens when you mix 5w30 with 10w30 oil?

It doesn’t matter whether the resulting oil is clean or whether it doesn’t affect human lives in any way. What a mixture of two oils truly does is cause the engine’s performance to decrease over time. It’s not just 5w30 and 10w30 combinations. Any raw oil combinations are notorious for engine performance in the long run.

While it doesn’t trigger much damage to your automobile’s engine, the overall efficiency increases. As a result, the engine force exerted upon operation decreases. This is because both these oils have different oil viscosity and will never mix. 

That is why you must use catalyzing agents and special additives. These additives decrease the excess viscosity so that both these oils can mix. While the additive does reduce the amount of burdening your engine experiences, you should avoid using mixtures of two oils in the long run.

A final note, even if you still decide to use this mixture despite all these warnings, you can kiss the warranty of your engine goodbye. Manufacturers will not cater to your warranty once you have used an oil or a mixture that the manual has not recommended.

5w30 vs 10w30 – Comparison Table       

If you are wondering how different the 5w30 oil is from the 10w30 oil, then this section is for you. Below have drawn out a table with a brief outlook into these two oil types:

5w30 oil 10w30 oil
It is a lubrication fuel for engines with a wide range of temperature It is a lubrication fuel for engines with a smaller range of temperature.
Since they have lower viscosity, they can flow into the hardest parts of the engine. Therefore they have higher efficiency. The higher viscosity means that they cannot reach all parts of the engine easily. Therefore they have a lower engine.
The engine works better for lower temperatures, especially during the winter. The engine works better for higher temperatures, especially during the summer.
Has a temperature range from -35 to 35 degrees celsius. Has a temperature range from -60 to 30 degrees celsius.
Can be used in engines that require light-duty petrol and diesel vehicle.  Preferred to be used for heavy-loaded vehicles like trucks and buses.

Key Differences  Difference Between 5w30 and 10w30

5w30 vs 10w30

Now that we are done with a brief outlook into the differences, it is time that we delved deeper into the matter. We have compiled a few of these key differences below as follows:


While both of these fuel types are vicious and share the same properties due to their similar carbon numbers, their temperatures differ from each other by a lot. This high-temperature difference is the main distinction between the two oils. 

5w30 is a viscous fluid with an extensive range of temperature within -35 to 35 degrees celsius.10w30, on the other hand, has different properties from the 5w30. 10w30 oil type covers a significantly smaller range of temperature. It can retain its standard viscosity at -16 to 30 degrees Celsius at the temperature ranges.

While these fuels have their fluid temperatures for standard viscosity, many of these temperatures points can also be affected by the external temperature.


Efficiency is one of the significant factors people think about when choosing the right base oil for any engine. 5w30 is highly viscous when compared to its counterpart. Therefore it can easily flow through the engine and even reach the farthest parts without any issue. As a result, 5w30 oil operates quicker with increased efficiency. 

On the other hand, if we are talking about 10w30 oil, it has far lower efficiency than the 5w30. This is because the lower viscosity of the fluid doesn’t allow the oil to flow within the engine quickly. As a result, more time is required before the oil can reach the entirety of the engine.


External factors like environmental temperature play a vital role when it comes to performance. 5w30 lubricant oil can provide the best performance with lower temperatures. If you want the best performance out of your vehicle in the summer, 5w30 is a good choice for a decent oil change. 

10w30 is more of a winter alternative. This is because it works best when the environment’s temperature is high. Note that even though the favorable temperatures are still there, if it rises or falls to the extreme, the fuel will not work. 

At extreme temperatures, oil or similar fuel becomes inactive and cannot provide energy. For a perfect performance, a mild temperature is the most ideal. 


While you can use any of their fuels for any engine type, there are still some recommendations that you can follow if you want to enjoy the best performance in your automobile.

5w30 oil has a lower weight when compared to the 10w30 variant. That is also the main reason why it has a higher viscosity. That is why 5w30 is more suitable for engines that run smaller automobiles like small cars and bikes. 

As for the 10w30 oil has a much high weight rating, which prevents it from flowing as quickly as the 2w30. Therefore it is recommended that you use this oil type for heavy-duty vehicles like trucks, buses, and containers.

Additionally, 10w30 is also ideal for use in old-generation diesel engines that required straight weights. Alternatively, you could also go for another conventional motor oil like mineral oil with different viscosity grades.


When it comes to lubrication, 5w30 motor oil has an improved performance over 10w30. 5w30 can withstand high-temperature changes since it is a thinner oil, whereas the 10w30 can only withstand high temperatures and not any changes with cold temperature.

That is why 5w30 is best suited for exclusive automobiles with lower fuel requirements. On the other hand, the 10w30 is a thicker oil, best suited for commercial automobiles with high fuel requirements and diesel with an increased number of carbons. 

What is 5w30?

5w30 is a fluid lubricant that is used in automobile engines that are manufactured for commercial use. If you wonder what oil you have always been using for your car engine, there is a high chance that it has been 5w30. This lubricant is one of the most commonly used engine fluids globally.

While most people call it 5w30, its actual name is SAE 5w30. The term SAE comes from the Society of Automotive Engineering, while the w30 is based on the thickness of the lubricant. The 5 in the name refers to the different viscosity grades of the multigrade oil. 

The 5w10 lubricant covers a range of temperatures that can go as high as 35 degrees celsius. That is why it is perfectly ideal for getting your vehicle running in the summer.

Benefits of 5w30 oil

5w30 engine oil have several advantages and you should know the benefits of 5w30 mentioned below:


If you intend to use the 5w30 lubricant, there are several benefits that you will get to enjoy. To start with, the lubricant forms an oily protective shield of continuous layers over the engine parts.

This helps reduce the friction that the engine and its smaller components experience. Since it has a low oil weight, the wear and tear in the engine motor get reduced. Therefore the fuel burns far more smoothly. 

Decreases Carbon Emission

The main reason why more people have turned towards the 5w30 is that it helps prevent the lifespan of your car engine from getting reduced.

The 5w30 has an incredibly tremendous thermal stability which means that it can retain its property even if the temperature changes over a long-range. This prevents the motor from consuming too much oil and helps control carbon emissions. 

Low-Temperature Resistance

In addition, the 5w30 has the property where you won’t be required to use too much of the lubricant. It lasts a long time without replacement. That is why it is the perfect lubricating fluid for low-temperature winters.    

What is 10w30 oil?  

The 10w30 is another lubricant variant of the 5w30. It used to be prevalent about a decade ago before being outclassed by the 5w30. However, that doesn’t mean that it is worse off in any way. Nowadays, most people prefer to use the 10w30 lubricant for heavy-duty vehicles like trucks and buses. 

Just like the previous entry, the 10w30 name has been taken from SAE 5w30. The 10 here refers to the fluid’s viscosity, while the 30 refers to its fluid thickness. 

lubricant covers a temperature range of The viscosity of the lubricant decreases as the temperature rises due to its unique property. As a result, it is better that you use the 10w30 during colder months rather than the summer. 

Benefits of 10w30 oil 

Like 5w30, 10w30 has also has some distinct benefits you should know. They are…

Lower Friction

10w30 lubricating oil has some of the most unique properties and functions that give people a decent reason. Just like the 5w30, it creates a continuous layer over the engine that shields the moving parts from feeling increased resistive force. As a result, the friction in the engine is kept to a minimum.

Increases Life Expectancy

You can start the engine anytime without worrying about wear and tear over the small motor components. Furthermore, the lubricant also helps increase the engine’s life expectancy by preventing the engine components from rusting.

Soundlessness And High-Temperature Resistance: 

What’s more, 10w30 promotes soundless motor operation by keeping the clutch gear smooth. 10w30 lubricant is suitable for biofuels like biodiesel that most large vehicles use.

Additionally, the lubricant can handle high temperatures well. That is why it is the most ideal for high-temperature climates.      

What Would Happen If You Used The Wrong Lubricant Or Blend? 

Under normal circumstances, where the lubricant oils have similar components, nothing much would happen. However, there are some exceptions to this. 

For instance, we have already said that 5w30 lubricant is preferred for vehicles in cold climates. However, if you used the 10w30 instead, the lubricant won’t last long since it has not been created while keeping the low temperature in mind. This means that you will need to change your lubricant constantly. 

However, this is only for using lubricants where the difference isn’t significant. If the difference between the required lubricant and the lubricant being used deviates by a lot, there are 2 likely problems you might have to face:

The car will refuse to start, especially when the climate is too cold. Even if the car starts, you won’t run it smoothly. It will feel like the car is heavy and will not accelerate properly. 

The engine might overheat if the lubricant starts burning instead of flowing through the engine. This could lead to more serious issues like engine damage and engine explosion.

Related: Best Penetrating Oil For Seized Engine And Other Bolts

Tips For Buying Engine Oil?

Can I mix 5w30 with 10w30? Yes, you can! However, engine oil is not advisable for the various reasons that we have already mentioned. In this section, we will be giving you some tips that you can follow when buying the right kind of oil:

  • The first thing that you should be noted down is the manufacturer of your car or the brand. New generation cars have a superior high-performance engine that does not have the need for some older oils. You might need to change your oil if you buy one without consulting the car manufacturer.
  • Is the place where you will be driving extremely cold or hot? Some lubricants are meant to be used for certain climates. You need to understand your environmental needs when finding the right engine motor oil to purchase. 
  • Viscosity grade is the most important factor of engine oil. Without appropriate viscosity, your engine components might start to create a spark and catch fire. Always check on the viscosity grade of your lubricant.
  •  Lastly, check on the label of the oil container that you are intending to buy. Take notice whether they meet the right standards placed by either API or ACEA. Anything other than these might not be worth your trust.  

People May Also Ask

Is 10W30 Thicker Than 5W30?

No, 10W30 is not thicker than 5W30. They have the same thickness under standard conditions. However, if the temperature is hotter, the conditions are favorable towards 10W30.

As a result, the thickness of 10W30 lubricants might increase compared to 5W30 at hotter temperatures.

Should I Use Thicker Oils In Older Engine?

Yes, you should always use thicker engine oil instead of regular oil or synthetic oil on old engines. Old engines tend to be prone to extreme heat.

If you use thicker oils like 10W30, the machine would be well-protected. In addition, it will also decrease the chance of further rusting in the engine and improve the pressure exerted on the engine as well. 

What Happens If You Use 10w40 Instead Of 5w30?

If you use 10w40 instead of 5w30, there are several cases that your vehicle might suffer from, starting with lower engine performance.

This is because these lubricants have different operating temperatures. As a result, the car engine might require some time before adapting to the new operating temperature. 

What Happens If Synthetic Oil Is Mixed With Regular Oil?

Mixing synthetic oil with regular oil will cause absolutely nothing, even though they are both different oils. The vehicle will not be affected whether you are thinking of it as bad or good.

Creating this blend is a waste of money as synthetic oil is slightly more expensive than most other thinner oils like the SAE 30 oil or the API SN. 

Does Engine Size Affect The Amount Of Lubricant You Will Require?

Not really; engine size will not affect the amount of lubricant you’re required to use. However, you are advised to use a lubricant that takes time to burn up, like 10w30.

These lubricants are thick at high temperatures of the engine and so take a long time before they evaporate. 

Final Words

Engine oils are crucially important if you want your car to run for a long time. While 10w30 and 5w30 are both good choices, there is always a chance that they might be the wrong oil for your vehicle. 

In these cases do your research well before you decide to buy from a different oil brand. Consider all the factors that might affect the need for engine oil like external temperatures, fuel economy, oil pressure, engine wear, and tear, etc. Additionally, you can also choose to take advice from automotive engineers. 

Only then purchase the oil. You won’t regret it later on!

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