Skip to content

Can You Mix Dexos with Regular Oil?

It is not recommended to mix Dexos oil with regular oil. Dexos oil is a type of oil that is specifically designed for General Motors (GM) vehicles. It is made with high-quality base oils and additives that help to protect the engine from wear and tear. Regular oil is not specifically designed for GM vehicles and may not provide the same level of protection.

Mixing Dexos oil with regular oil can cause the following problems:

  • The oil may become cloudy or milky.
  • The oil may lose its viscosity and become less effective at lubricating the engine.
  • The oil may form deposits in the engine.
  • The oil may cause the engine to overheat.

If you are unsure whether or not you can mix Dexos oil with regular oil, it is always best to consult your car’s owner’s manual. The owner’s manual will specify the type of oil recommended for your car.

If you do decide to mix Dexos oil with regular oil, it is crucial to do so gradually. Start by adding a small amount of the new oil to the old oil, then run the engine for a few minutes. If there are no problems, you can add more of the new oil.

It is also important to change the oil filter when mixing different oil types. The oil filter will help to remove any contaminants that may be present in the new oil. By following these tips, you can help to minimize the risk of problems when mixing different types of oil.

The Potential Risks of Mixing

Understanding the properties and purposes of both Dexos and regular oil sets the stage for our main query. So, can these two oils be mixed safely?

To put it briefly, while it might not result in immediate damage, mixing Dexos with regular oil is not recommended. Here’s why:

  1. Dilution of Performance Benefits: Dexos oil is designed with specific additives to optimize GM vehicle performance. Mixing it with regular oil dilutes these benefits, potentially reducing the engine’s efficiency and longevity.
  2. Viscosity Variations: Each oil has a specific viscosity. Mixing them could create an inconsistent viscosity, which might not offer optimal lubrication. This can put additional stress on engine components.
  3. Chemical Reactions: The unique additives in Dexos might not be compatible with those in regular oil. This incompatibility can lead to unwanted chemical reactions, which could, over time, compromise the engine’s health.

The Verdict on Mixing

Given the potential risks outlined above, it’s clear that mixing Dexos with regular oil isn’t a wise choice. If your vehicle is designed for Dexos oil, it’s best to stick with it to ensure your engine’s optimal performance and longevity. Conversely, if your car requires regular oil, there’s no tangible benefit to introducing Dexos into the mix.

Recommendations for Car Owners

For those who own vehicles, here are some key takeaways:

  • Always Consult Your Vehicle’s Manual: Before making any decisions regarding oil, always refer to your vehicle’s manual. It provides specific recommendations tailored to your car’s engine.
  • Stick to Consistency: Once you’ve chosen an oil type, try to remain consistent in your subsequent oil changes.
  • Regular Maintenance is Key: Whether you opt for Dexos or regular oil, the key to a healthy engine is regular maintenance. This includes timely oil changes and routine check-ups.


While the automotive world offers many choices and combinations, certain mixtures like Dexos and regular oil are best avoided. For the sake of your vehicle’s performance and lifespan, it’s wise to heed manufacturer recommendations and resist the urge to mix and match. Remember, consistency is crucial, and when in doubt, always refer back to your vehicle’s manual.