Does Motor Oil Have a Shelf Life?
Motor Oil has a shelf life specified by manufacturers on average of 4-5 years. Oil manufacturers recommend using the motor oil within 5 years because of the additives the oil contains. However it is arguable that since the oil never goes bad, it can be kept indefinitely as long as stored properly.
As long as oil is properly sealed and stored in a manner to prevent moisture from contaminating it, engine oil will stay good forever.
I have personally used motor oil that had been sitting for more than 20 years. I found some of the bottles of oil that had been sitting had become brittle and were breaking down but the oil inside was just fine. I have tested this myself and found that old engine oil can be used as long as it can be stored and kept from contamination of air or water.
If using old oil simply shake it up before you use it to re-mix the oil additives that separate after a long period of sitting. And check the oil for water by pouring it into a clear container before using in your engine. The main thing to look for is if water has entered the oil. Since water is more dense, it will settle on the bottom of the clear container.
What is motor oil shelf life according to the top motor oil manufacturers in the U.S?
This table indicates the advertised shelf-life of motor oil according to the manufacturer whether advertised on a product, or their website, or in response to a tech support inquiry.
|Engine Oil Brand||Advertised Shelf-Life|
|Gastrol GTX||No Advertised Date|
|Quaker State||Up to 4 years and not necessary to shake|
|Amazon Basics||No Advertised Date|
|Pennozil||5 years from tech support|
|Lucas||No Advertised Date|
|Shell||4 years on properly stored unopened oil from tech support|
Valvoline says there is no documented expiration date!
Havoline oil includes a shelf life of 60 months (5 years) after the date of filling.
STP advertises a standard 5 year period for most of their products all included in a table on their website.
Valvoline does not provide an expiration date because they are aware just as we are that motor oil does not “go bad” and we do not have to go buy new oil simply because it sat unopened for 4 or 5 years.
“When stored under optimal conditions, the product remains stable for an extended period of time. It can be used as long as the American Petroleum Institute (API) rating on the label continues to meet or exceed the requirements listed in your car’s owner’s manual. If the rating is still current, we advise you shake the container before use to blend any additives that may have settled.”Valvoline FAQ
So, although motor oil has a shelf life, it is for far longer than some manufacturers state with the expiration dates on their motor oil bottles. Store it properly and the oil is stable for a very long time.
How Long is Mobil 1 Oil Good for in the Crankcase?
Oil in a Car in Storage
5 years is the maximum amount of time oil should be left not being used in the crankcase. The oxidation process occurs rapidly in oil that has been used. The combination of dirt, coolant, water and metallic particles in the oil causes the oil to break down. If the oil has sat in the engine for more than a few years it should be replaced.
Engine oil should be drained or replaced before storing a car for more than a few years and if the car has been stored with oil in it, should be replaced before driving the car to ensure proper lubrication and prolong the life of the car engine.
Of course the engine may still run with old oil but fresh oil will result in the least amount of wear on the engine. Just replace it!
Oil in a Car in Use
A car continually in use is generally easier to regulate the time that the oil is good by the number of miles driven. Conventional motor oils on average recommend an oil change every 3,000 miles and a synthetic oil can be up to 10,000 miles. I prefer to use synthetic oil and change it whenever it seems dark and at about 6,000 miles.
More frequent oil changes results in a longer life for the car engine!
Change the engine oil frequently!
What Causes Old Motor Oil to go Bad
Unopened motor oil does not rot or spoil or go rancid. Opened oil will slowly oxidize and used oil will oxidize and break down much quicker as it is used in the engine and eventually leads to oil sludge. Old motor oil may require mixing since it contains additives that separate from the oil.
Does Oxygen Affect Old Oil?
Oxygen causes oxidation which is a chemical reaction. On metal, results in rust. On apples, results in them turning brown. On motor oil, breaks the oil down to be thicker and more viscous. And leaves a sludge preventing the oil from being able to lubricate properly and transfer heat.
Oxygen does permeate (pass) through the plastic container that motor oil is stored in. VERY slowly oxygen enters the oil container. The good thing here is that the permeation of oxygen through a sealed motor oil container is so slow that it will not have a significant effect. Unopened motor oil can essentially be stored indefinitely.
Opened oil does break down and become contaminated and should be used within 1-2 years of opening. If the container is left open, oxygen does have an effect on the motor oil, so an opened container of oil breaks down and water is able to contaminate the oil.
Old, USED oil breaks down/oxidizes much more quickly due to particles of dirt, metal, fuel, or coolant in the oil. Used oil cannot be left open for more than a few years and should be replaced with fresh oil rather than using it.