Does Synthetic Oil Degrade Over Time? (How Long? Explained!)

Car owners ask if synthetic motor oil does expire or degrade over time. Some people say that it does degrade, and some do not. So let us find out the answer.

So does synthetic oil degrade over time? Unfortunately, the answer is that there’s no exact and straightforward answer. This is because the longevity and the life of synthetic oil depend on a lot of factors. 

So in this article, we’ll be discussing the factors that can affect the condition of synthetic motor oil. This article is worth reading because it’s essential to consider that expired motor oil will not do the proper lubrication that your vehicle needs. So let us begin.

Does Synthetic Oil Degrade Over Time

Does Synthetic Oil Go Bad Over Time?

Synthetic motor oil can break down over time. This can be because of a lot of reasons. It has something to do with motor oil and the additives that make up the lubricants. 

So if you will use your vehicle, there are hydrocarbons and water that can contaminate the motor oil. Many experts would say that you have to change your motor oil at least once in one year. However, there are many factors that you have to consider, like the distances of your travels. 

How Many Years Does Synthetic Oil Last?

There is no definite and exact time for how long synthetic lubricants must last before it expires. Some of the manufacturers like Mobil say that their synthetic motor oil can last for five years. Some other manufacturers were also sad that their products could last forever. 

But it must be stored in a specific condition. The longevity of the motor oil will depend on a lot of factors. If you want your synthetic motor oil to last for a long time, you need to follow your manufacturer’s instructions. 

You also need to ensure that you will check the expiration date of the bottle. Do not purchase or use synthetic motor oil if the expiration date is crossed. If there is expired motor oil, the oil will not be able to protect your engine. 

Synthetic lubricants are formulated artificially. They will come in various additives, and they will meet the needs of your engine. These additives will affect the longevity of your synthetic oil.

Also Read: How to Unseize an Engine That Ran Out of Oil?

Does Synthetic Oil Need To Be Changed Every Year?

There are a lot of myths about when you should change your synthetic oil. If you want to know the answer, you need to find your owner’s manual, and you have to look inside for the answer. Sometimes, the interval will range from six thousand (6,000) to sixteen thousand (16,000) miles. 

Many modern vehicles would have change intervals in the seven thousand five hundred (7,500) to ten thousand (10,000) mile range. If you have an older vehicle, you will need to consider that one of the synthetics is billed as a high mileage motor oil. 


In summary, a lot of people wonder whether synthetic oil would degrade over time. Some people believe that there are brands that can last forever. 

But there are a lot of conditions. So the longevity of synthetic oil will depend on a lot of factors. Read the sections above to know more.


Image credits – Canva

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My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more