Can You Mix 5W30 And 0W20? (Here’s The Answer)

It might be a hassle to figure out the type of oil to use for the right environmental temperature. The number of different oils might be confusing, but it is quite easy if you know what you are aiming for.

The letter W in the name stands for Winter, and the number right before the W shows the viscosity of the oil in winter. Meanwhile, the next double digits number shows the viscosity of the fuel at high temperatures, as noted by the SAE (Society of Automotive Engineers).

Since engine oil is the second most important fluid for your car, succeeded only by fuel. It is vital to know which one suits your engine.

So, can you mix the two?

Yes, you can mix 5W30 and 0W20 whenever you need to top up your engine oil level and can’t find the right one. However, there are some things to keep in mind. Both oils should be the same brand and the same type (you can read more here about the different oil types).

However, if doing an oil change, mixing different oils is not recommended. You should always use the same viscosity, brand, and oil type.

Is 0W20 the same as 5W30? What is the difference?

The main difference between these two oils is the viscosity of both. Oils with low viscosity flow well in low temperatures, while oils with high viscosity flow better in higher temperatures.

Highly viscous oils get thinner with high temperatures and provide adequate protection to engine parts. However, with lower temperatures, they maintain their thick consistency and drag through the engine, reducing the performance of the engine.

Meanwhile, oils with low viscosity are thin enough to flow through the engine without issue, but in high temperatures, they get thinner and do not provide sufficient protection to engine parts. Using the wrong engine oil in extreme temperatures could lead to engine damage in the long run.

Viscosity difference

To properly understand the right oil for you, it is important to bear in mind that winter-grade oils are usually thinner than oils suited for higher temperatures.

Having considered the number included in the oil names, 0W20 has a lower winter number than 5W30, indicating that 0W20 is better suited for use in winter periods than 5W30 because the 0W20 has a lower viscosity than the latter.

5W30 oil in turn has a higher figure for its suitability for high temperatures, indicating that the oil is better suited for high temperatures than 0W20 oil.

Please note that the difference in viscosity does not impact the ability of both fuels to adapt to both warm and cold climates. Both oils are multi-grade fuels that can operate effectively in both warm and cold temperatures. However, they do not adapt at the same level. 0W20 adapts better to very cold climes, and 5W30 adapts better to very warm climes.

Fuel consumption

Oils with lower viscosity have higher efficiency; thus, they do not affect the fuel economy of the car. Therefore, 0W20 is about 10 to 20% more efficient than 5W30 due to its low viscosity. However, despite the low fuel consumption from the use of 0W20 oil, the cost of the oil is higher than the cost of 5W30 oil, thereby giving approximately similar costs.

Related content: Can You Mix 5W20 AND 5W30 Oil?

What happens when you mix them?

Mixing both fuels has no impact on your engine as long as they are mixed well. To optimize the advantages of both fuels, some users prefer to mix both fuels. However, before mixing both fuels, check the recommendation of your automaker. If both fuels are listed as suitable oils for your engine, there should be no harm in mixing both oils in the short run.

If you wish to mix both fuels, ensure both oils are synthetic. Synthetic oils and conventional engine oils do not mix well for your engine. Synthetic oils are the premium line for engine oils, while conventional engine oils are at the bottom of the chain. 5W30 has a regular variant which is not suitable for the synthetic variants of 0W20 oil. Mixing contrasting variants could harm the engine in the long run and could even render the warranty of your car invalid.

What ratios can you mix?

The ratios of the mix of both fuels depend on your preference. However, you might start with a 10 to 1 ratio and observe the performance of your engine before increasing the ratio. Your usual oil should be the larger fraction, while the newer oil should be the lower fraction.

Please note that mixing these oils is not essential as both oils are multi-grade oils that operate effectively in warm and cold climates. But in cases of emergencies and you are out of your usual oil, you can top up with the other oil till you get your usual oil.

Can you use 0W20 instead of 5W30?

Before swapping oils, it is best to confirm with your car’s manual. Both oils are efficient multi-grade oils that can easily adapt to cold and warm climates. However, the degree of their adaptability differs for each oil.

5W30 oil is better suited for warmer climates; hence the use of 0W20 in hot regions might not be suitable. You’ll observe a drop in performance if you swap oils. The higher viscosity of 5W30 gives engine parts sufficient protection while in operation.

Can you use 5W30 instead of 0W20?

Since both oils adapt well to warm and cold climates. You might not notice any difference with an oil change. However, in cases of a very cold winter, there will be an obvious drop in performance if 5W30 oil is used in place of 0W20 oil.

In colder temperatures, 5W30 will not move as smoothly as 0W20 due to its thicker consistency, the oil will drag through the engine and lead to lower performance. On the other hand, being thinner, 0W20 oil will move through the engine faster and contribute to performance.


Picking the right oil for your car might be tricky, especially if you do not know what condition is better suited for each oil. The best place to start your selection is by taking a look at the recommendation from your car’s manufacturer. You could check your manual or call your local dealership to confirm which oils are better suited for your engines. If any of both oils are not acceptable by the manufacturer of your vehicle, the use of the oil could render your warranty invalid.

Even if you recently changed your car, do not use the same oil you used for your previous car because it worked well for it. The engines of various car models differ, and oils better suited for one model might not suit another.