As an expert in automotive maintenance, I'm often asked about the nuances of oil and its proper use. Let's dive into the topic of mixing different brands of motor oil.

Motor oil is a complex fluid that serves multiple critical functions within an engine. It lubricates moving parts, helps to cool the engine, and also cleans and prevents rust. The oil is formulated with a specific balance of base oils and additives to meet certain performance standards. These standards are set by organizations like the American Petroleum Institute (API) and the Society of Automotive Engineers (SAE), which ensure that the oil provides the necessary protection and performance for your vehicle.

When it comes to mixing different brands of oil, there are a few factors to consider:


1. Base Oil Compatibility: The base oil is the primary component of motor oil and can vary between brands. While the base oils themselves are generally compatible, the additives are what can cause issues.


2. Additive Systems: Each brand of motor oil has its own unique blend of additives. These additives are designed to work synergistically to provide the best performance and protection. When you mix oils, you risk disrupting this balance, which could potentially lead to reduced performance or even engine damage over time.


3. Quality and Grade: It's important to ensure that any oil you add to your vehicle is of equivalent quality and meets the same grade as the oil that is already in the engine. Using a lower quality or incorrect grade of oil can lead to issues such as increased wear, poor lubrication, and even engine failure.


4. Seal Compatibility: Some additives can be harsh on engine seals. If the additives in the mixed oils are not compatible, it could lead to seal degradation and oil leaks.

5. **Engine Manufacturer's Recommendations**: Always check your vehicle's owner's manual for the manufacturer's recommendations on oil types and brands. Some manufacturers may specify that only certain oils should be used.

Now, to address the myth and fact you've mentioned:

Myth: You can't mix brands of motor oil.
Fact: While it's not the best practice to mix brands due to potential differences in additive systems, adding a small amount of a different brand of oil of equivalent quality between oil changes is unlikely to cause serious problems. However, it's always better to use the same brand and type of oil throughout the life of your engine to ensure optimal performance and protection.

In conclusion, while it's technically possible to mix different brands of oil in certain situations, it's not recommended due to the potential risks involved. It's best to stick to a single brand and type of oil that meets your vehicle's specifications to ensure the longevity and performance of your engine.

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Myth: You can't mix brands of motor oil. Fact: Mixing brands is not the best practice because the additive systems in each may be different and when mixed may not function as efficiently as desired. However, no serious problems will occur if you must add a different brand of equivalent quality between oil changes.read more >>