Oil Shelf Life
 

I have been wondering for a time now but just remembered finally to ask; the ol memory just isn't what it used to be. Does an unopened bottle of oil break down or degrade in any way if it is just sitting on a shelf in a basement where it is not exposed to sub freezing temps or too hot of temps? Is it safe to use to add to an engine to bring the level up to full if it has been sitting for say 4-5 years? What about if the bottle has been opened, some oil used, top reinstalled and sitting for 4-5 years? What do you guys think?

I have always wondered that too.

Gregg

The issue is water. Water will eventually go through the plastic bottle in sufficient quantity to mess up the oil. If the oil is somehow special (expensive) then I would keep it for about 5 to 7 years and then pitch it. If you do have something you want to keep like this for a very long time put it a 1 gallon metal paint can (empty ones with lids at Home Depot or Lowes) and close it up. Steel is for all intents and purposes impermeable to water.

Water will travel through the sealed plastic container? If so, won’t the little amount of water evaoarate out of the oil once it’s in a hot engine?

Thanks,

Jason

I recently used some old oil (25 plus years) in plastic bottles that had been stored in a semi climate controlled area (attached garage). Poured the first bottle in a pan to see how it looked. No evidence of water intrusion. Had there been water present, it would have sunk to the bottom. They don't stay mixed absent some agitation. It was fine. Not sure I would trust one of the old card board can containers.

I believe as long as it is not subjected to extremes in temperature, there is no problem.

Of course, the smart arse in me wants to say: It has been stored underground for 68 plus million years; how bad can it get after another 20 on the shelf?

Yes, it will and it depends on the humidity and temperature.

Most all materials have some level of WVTR...water vapor transmission rate. The water molecule is very small and can pass through the pores of the plastic.

AC systems have desiccant due to the hoses and rubber seals. Folks are surprised that a system that has around 150-300 psi pressure still lets water in.

The water will burn off and there are detergents and additives to deal with it. For the daily driver I wouldn't worry about it.

Thanks guys for your comments.

Good info to know. Thanks.