Can You Put 10w30 in a 5w30 Engine?

by Synthetic Oil | Last Updated: June 5, 2022

Knowing which type of motor oil your engine requires is essential. Since choosing the wrong viscosity could negatively impact the performance of your vehicle, you also might have questions like, “Can I put 10w30 in a 5w30 engine?” The 30 at the end of that classification is the viscosity, meaning that these two kinds of engine oils have the same thickness. Therefore, the answer is yes, you can put 10w30 in a 5w30 engine.

But let’s talk about why that is possible, as well as what happens if you do.

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What is 5w30?

Used most in automobiles of various shapes and sizes, 5w30 is a very common grade of motor oil. The 5w means that it runs thin in cold temperatures. A grade of 30 is the viscosity when warm. Both 5w30 and 10w30 run the same in hotter conditions.

Benefits of 5w30 Motor Oil

By forming a layer of lubrication around the functioning parts of your vehicle’s engine, 5w30 protects it from friction, excessive heat, general wear, and tear, and also sludge buildup. Aside from that, 5w30 has incredible thermal stability, meaning that the oil properties remain the same, regardless of how hot the engine or ambient temperature becomes. As such, 5w30 helps with fuel and oil consumption.

5w30 is suitable for engines that consume gasoline, as well as light-duty diesel engines. Since this oil remains thin in cooler temperatures, you should use this if you live somewhere with a colder climate.

What is 10w30?

10w30 motor oil is often used with engines that sustain heavy loads, including machinery and manufacturing equipment. This oil is designed for high temperatures and to preserve the performance of your vehicle’s engine. 10w is the viscosity for when the engine is cold, and 30 is for when the engine heats up (or works at a high temperature). 10w30 is a little thicker than 5w30.

Benefits of 10w30 Motor Oil

10w30 oil has some unique benefits that separate it from 5w30. First, as with all engine oils, 10w30 protects your engine from rust build-up and friction. Due to the decrease in friction, gears shift more smoothly and quietly, as well. 10w30 is most suitable for use in hotter climates.

What Are The Differences Between 10w30 and 5w30?

There is not much of a difference between these two grades of oil. Both are multigrade and multi-functional. You can expect decent protection in both hot and cold temperatures, too. However, 5w30 is a little better in colder temperatures, though most people live in regions where either 5w30 or 10w30 work the same. Furthermore, 5w30 is slightly better at lubricating the engine of your personal car. 10w30 is better suited for commercial fleets and heavy load engines.

Can You Put 10w30 in a 5w30 Engine?

Yes, you can put 10w30 in a 5w30 engine, but should you? It depends. Let’s say you are in a pinch. You know for certain that your car takes 5w30, but only 10w30 is on the store shelves. That, or you find the price of 10w30 far more budget-friendly. Again, you absolutely can substitute 10w30 for 5w30.

Now let’s talk about the downside to this swap. Using the recommended motor oil grade maximizes your vehicle’s fuel consumption, but is there any other reason you shouldn’t use 10w30 in place of 5w30? Cold starts. If you have a cold start, 10w30 may not be as beneficial as 5w30. The thicker the oil, the slower it flows through the engine and hinder performance. Otherwise, in the summertime, there really is no difference.

The other time you may consider using 10w30 instead of 5w30 is when you have an older engine. Since 10w30 is slightly thicker, its sealing capabilities are better for engines with high mileage.

Can You Mix 10w30 and 5w30?

Mixing oil with different weights is a common topic of discussion. Should you mix a 20 and 30, for instance? This often is a poor idea, as you create a new viscosity that may potentially harm your engine. Mixing 10w30 and 5w30, however, is different. Since you are mixing oils with the same viscosity, the end result has the same weight. You might get an oil that is slightly thicker than 5w30, depending on how much 10w30 you put in, but it won’t be as thick as 10w30.

That said, as tempting as it may be to mix oils when you have dozens of half-full bottles lay around, you should not make it a habit. Only mix oil grades when you need to top up. Never do this during a full oil change. If you need to use all 10w30 even when the manufacturer recommends 5w30, that is what you do.

Bottom Line

You should now know that yes, you can use 10w30 instead of 5w30 for your car. However, your car may not function the same in colder temperatures. Since the viscosity at higher temperatures is 30 for both, it is best to swap 5w30 for 10w30 during the warmer months. All in all, be it 5w30 or 10w30, either is better for your vehicle than no oil at all!