Can You Put 10w30 in a 5w20 Engine?

Naomi O'Colman

Can You Put 10w30 in a 5w20 Engine

Can You Put 10w30 in a 5w20 Engine

Are you always trying to find out the answer to the question “can you put 10w30 in a 5w20 engine“? So you have some oils left of each type or you’re on the road and in need of topping up. This article will give you the answer.

As mentioned in other blogs, mixing oils is not recommended but you can mix them sometimes without causing harm to the engine. So, 10w30 & 5w20 can be combined together.

Can You Put 10w30 in a 5w20 Engine?

Even though these two oils are different in viscosity, you can mix them together. A 10w30 engine can easily take a 5w20 oil or vice versa. The difference in weight of these two oils is only 8.7%, which is not that significant. In the case of a 10w30, it will have a viscosity of approximately 10w28, and a 5w20 will have a viscosity of approximately 5w22.

The viscosity 10w28 is quite close to the one of a 10w30. The difference in weight between a 5w20 and a 5w22 oil is larger than the difference between a 10w30 and a 10w28. So, there is no reason why you cannot mix these two oil types.

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The differences between these two oils are mostly in additives and not in the base oil. So even if you put a 5w20 oil in a 10w30 engine, it will not cause harm to the engine. However, we do not recommend this mix for extended periods of time.

Helpful Tips

Here are some helpful tips that will help you determine whether or not your car’s oil capacity is the same as the amount of oil listed on the bottle.

  • Read your owner’s manual. If the book says 5w20 (like most modern vehicles), then it’s best to use 5w20 for your engine.
  • Locate how much oil is required for your particular model of car, also known as the operating range.
  • If your car’s owner’s manual states the oil capacity as 5w20, it means that it will hold up to five quarts of oil for a full-time duty cycle of your car. In other words, if you drive it for 15,000 miles each year, and drive as much aggressive driving as possible–the oil capacity will be around 5 quarts.


To conclude, mixing 10w30 & 5w20 oils is allowed. You can do this without any worries. However, it is not recommended you do this for an extended period of time. Just make sure to mix them at least 3 months before you actually need to use them together. If you don’t, the oil life will be shortened by shortening the mixing time between each of these oils.