Can You Mix Car Engine Oils?

The Short Answer

Yes, you can mix car engine oils, but it’s not always a good idea. Mixing different types of oil can lead to problems with your engine.

When You Can Mix Car Engine Oils

There are a few situations where it’s okay to mix car engine oils.

If you’re adding a small amount of oil to your engine. If you’re just adding a quart or two of oil to your engine, it’s probably okay to mix it with the oil that’s already in there. Just make sure that the oils are compatible.
If you’re changing your oil type. If you’re changing from one type of oil to another, you may need to mix the two oils together. This will help to prevent sludge from forming in your engine.
If you’re using an oil additive. If you’re using an oil additive, you may need to mix it with your engine oil. This will help to ensure that the additive is evenly distributed throughout your engine.

When You Shouldn’t Mix Car Engine Oils

There are also a few situations where you shouldn’t mix car engine oils.

If the oils are not compatible. Not all car engine oils are compatible with each other. Mixing incompatible oils can lead to problems with your engine.
If the oils are of different viscosities. The viscosity of an oil is a measure of its thickness. Mixing oils of different viscosities can lead to problems with your engine.
If the oils are of different ages. As oil ages, it breaks down. Mixing old oil with new oil can lead to problems with your engine.

If You’re Not Sure

If you’re not sure whether or not you can mix car engine oils, it’s always best to consult with a mechanic. A mechanic can help you to determine which oils are compatible with your engine and how to properly mix them.

Conclusion

Mixing car engine oils can be a risky proposition. If you’re not sure whether or not you can mix oils, it’s always best to consult with a mechanic.