Many motorists have been asking me this question; does motor oil expire or get old?
My answer is No, motor oil does not expire but has a period where it can be very effective and after that, it becomes less effective. So, if you consider that as your expiry date, then it has one. But in the real sense, if oil is kept at optimal temperatures and properly sealed, it can be used after several years.
The things that make motor oil to expire or become less effective are excess heat and stress of operation for several miles that can actually oxidize the oil, causing it to thicken and lose its stability to move within your car engine. Furthermore, the more the oil picks up debris in the engine, the more it continues to become less effective and even changes color. That’s why it is recommended that engine oil should be changed after every 7,000 miles for normal car operations and 5,000 miles for vehicles that operate under sever conditions like very hot, very cold, short trips and extremely dusty places.
Other things that may determine the expiration of motor oil include contaminants like water, heat, oxygen and light. This can make the oil to oxidize or change its properties and thus not lasting for so long. If kept well and not interfered with, motor oil that has 3 to 5 years can still function perfectly in most cars. It’s important when buying motor oil, you should check that the oil meets or exceeds the requirements listed in the owner’s manual. Also, a good number of lubricating oil has a shelf life of 3 years.
To conclude, there is no specific date for the expiry of motor oil. But the recent motor oils are thin and may have not encountered some of the factors that make oil to be considered unfit for use. Motor oil that hasn’t been for use for a long period of time might have turned thick and it is not good for the engine. So, unless you are sure that the old oil you’ve in your store hasn’t been contaminated, then you can utilize it.