Does Synthetic Motor Oil Ever Expire?


All drivers have had the experience of needing to change their oil. Some drivers opt for a professional oil change through their local car mechanic while other drivers opt for a do-it-yourself oil change.

Regardless of the method you choose to change your oil, you have likely encountered questions when it comes to changing your oil. One of the most common questions that drivers ask about oil is whether synthetic motor oil can go bad.

How do you know if synthetic motor oil expires? Unfortunately, there is not a straightforward answer since the longevity of the oil is influence by a variety of factors. Below we discuss some of the factors that must be considered before determining whether synthetic oil can still be used. This is an important consideration given that expired oil might not have the protective factors that can help protect your car.

Does Synthetic Motor Oil Ever Expire

What Factors Are Important in Oil Expiration?

One way to avoid the problem of oil expiration is to only purchase the amount of oil that you will need in order to change your oil for this one time. However, given the cost savings of buying oil in bulk, some drivers prefer to stock up on the oil. In general, you should expect that your oil will last at least five years.

This five-year suggestion is based on the assumption that you store the oil according to the storage instructions that come printed on your motor oil can.

If your motor oil comes with an expiration date printed on the container, which is less than five years, you should abide by the printed date. After the date on the container has passed, make sure that you properly dispose of the oil. After the expiration dates have passed, there is no longer a guarantee that the synthetic additives will still function properly.

When thinking about shelf life, it is important to understand that the composition of motor oil does not last forever. Things such as the specific additives will determine how long the motor oil will last. While these are two of the most important factors in determining the life of the synthetic motor oil, there are some other factors involved.

One of the factors that you have the most control over is the temperature at which the motor oil is stored. Storing the oil somewhere between 40 – 85 degrees Fahrenheit is the best option. You should also make sure that you find a place to keep the oil where the temperatures will not be variable. This is because very low and very high temperatures can impact the oil’s ability to lubricate the engine.

As you might expect, bottles of oil that have not been opened tend to last longer than bottles of oil that have already been opened. Thus, you should try to open only one bottle of oil at a time and use any opened bottles for your next oil change. This will prevent you from having multiple bottles of opened motor oil.

When storing your oil, there are a couple of other important factors to consider. One is that you will want to store the oil in an area that is not prone to humidity. If humidity seeps into your oil, you might experience alterations in your oil that could lead to added microbes or sludge.

Both of these pose problems for your engine. Lastly, you will want to keep the oil away from dust. Any dust that makes its way into your oil is certain to aid in clogging your engine more quickly.

How Will I Know if My Motor Oil Is Expired?

While it can be hard to tell for certain if your oil is expired, there are some steps you can take to determine this. First, look for an expiration date. If the date has passed, throw the oil away. Alternatively, if you have had the oil for more than five years, it is time to dispose of the oil.

If you are unsure, check for the color of the oil. If the oil looks clear, it is likely good to use. However, if you see haziness in the oil it could be an indication that water has gotten into the bottle. Another good indicator of whether the oil is suitable to use is the consistency. If you notice any separation in the motor oil, that is not a good sign and you should throw away the oil. Similarly, oil that is solid, think, or very sticky is also not good to use.

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