Yes for permeation.

Moisture (vapor) travels from warm (moist) to cold (dry)...at least that's how it works in an insulated wall (and why you need a vapor retarder in wall construction in certain climates.

Should be better in a controlled environment.

It has a lot to do with molecule size. Oil is a HUGE hydrocarbon chain, whereas water is a simple 3 atom molecule. The holes in the plastic bottle are miniscule, and the amount of water that travels through it is ALMOST immeasurable, but rest assured, it is happening. Different bottle plastics will permeate at different rates, think ketchup bottle versus milk jug.

Easy example is a latex baloon. They will deflate naturally, as the air passes through the holes in the rubber molecules. Have you ever noticed how much faster a helium baloon deflates? It is because the helium atoms are TINY and pass through the holes much easier and faster. Mylar baloons will deflate much slower since the metallic surface has MUCH lower permeability compared to platic hydrocarbon chains.

Dang sciency stuff...

https://www.reference.com/vehicles/motor-oils-shelf-life-e4589115d4577487

I wanted to drill down to what is exactly the shelf life of multi grade oil. The above URL explains a lot of it and it really is nice to know for some of us who rush out to buy oil only to come home and then keep it on a shelf for 4 years. The OP did say he was going to keep it from Spring to Fall which is like 6 months. Hey no worries. How the conversation turned to permeation and absorption still boggles the mind. But yeah, it has a shelf life.

because it's Moparts silly rabbit!

There is a lot of BS in this thread.

That website is so wrong on the first 2 items, kerosene will last a heck of a lot longer than 2-5 years even sitting in a vented tank with water at the bottom.

And motor oil will last way more than 5 years, way longer. More like 30 years at least because I have been using NOS motor oil since 1990, 5 different brands of oil. Not just one kind. I have used old oil in heavy duty diesel engines and then all the way to the smallest of generators.

I don't have to read it on the web to know because I have been doing it.

Like I said, oil stays oil, only the added stuff falls out. Even oil that has water, once heated, will evaporate out.

This afternoon at work, before I posted on this thread.

I took a 27 year old quart of Unocal76 20W-50 sealed and opened it and poured it into a white clean 3 gallon pail. I did it very carefully and checked it out several times as I was pouring it. There was absolutely no separation whatsoever and there was nothing on the bottom of the plastic quart container after at least 25 years of sitting in my work garage and I bet it sat in a warehouse somewhere before I got it.

I work at/own a oil company and we stopped selling/retailing motor oil at about 1990. I have been using our old stock ever since. Most of that old stock was from the late 80s.

I don't normally stop and scrutinize the oil as it comes out of the container but I did today.
27+year old oil, have built at least 3 old mopar motors with this oil and have never lost a new cam or any cam with it. All my motors are still running today that I built using this oil.

I also used cases and cases of 15-20 year old rotella in heavy duty diesel engines for millions of miles with no problems. Have never lost a motor. Ran 16800 hours on the last in frame overhaul and the first 10000 hours were on old oil.

Once again anecdotal experience wins out over science/chemistry.

16884 hours(320000 city miles plus PTO time) on these engine parts that used old oil early in it's life. Real world results, not science and chemistry.



I have overhauled countless motors in my time. I got a bit of a clue.

I also have a 200 gallon motor oil tank in my shop that has been vented to the air for 25 years that gets filled about every 12 months. So a little humidity does not hurt the oil. Water and oil do not mix.
In 25 years we have never had any moisture issues in our bulk motor oil tank and we pressure wash it clean on the outside some times along with the whole shop.

So what would happen if the plastic container lets in small amounts of air and moisture?

Science isn't infallible.
do you have a link to any chemistry tests you have performed, on this subject?

"also used cases and cases of 15-20 year old rotella in heavy duty diesel engines for millions of miles with no problems."
Like to have a couple cases of the old stuff for my diesel truck
And, who does the test, non other than the man selling the oil.

Well, to recap, some "say" oil has a shelf life with little to back it up, some others "say" it has a shelf life with questionable reasoning, some "believe" the questionable reasoning outright, and some ask questions that boggles some people's minds. Make's sense to me.

https://en.wikipedia.org/wiki/Hygroscopy

The problem with anecdotal experience is that each person's experience, to them, is the only valid observation to be considered and seems to be the only argument that is to be heard.

On the subject of additives dropping out of suspension, here's a couple of other anecdotal experiences for you to peruse:

https://bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2460094

https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=52788

I have fresh oil sitting in a 69 dart since 1988...pulled the engine dipstick and its crystal clean..

I am still amazed at all the fine folks on here that keep oil around for 25 years and swear by it. I've never considered it. Don't know why people would do things like that to begin with. Eventually, everything has a shelf life and goes bad. Even oil does but when exactly might be up for debate. If I pulled into a garage for an oil change and someone put 25 year old oil into my car, I would be seriously displeased. The API service criteria 25 years ago is nothing like the ones today making the oil back then obsolete for modern engines.......probably rebuilt ones too. My 2 cents.

What if you have a 25 year old engine?

It is a well known fact that 25 year old oil contains many needed chemicals that are now banned and may have been replaced by something not banned but inferior. Or simply left out.
And on the flip side I am not anxious to go back to non detergent oil of the 50s and before.
Oil today is the best it can be with the rules the manufacturers must follow.

I am the only "folk" who keeps oil for 25 years and so would you if you were in my shoes. I am not suggesting to use 25 yo oil in new cars and trucks today and I don't.

I was trying to make the point that if you got 10 year oil on the shelf to not throw it away it can be used in our old cars and trucks.

Not in our new cars.

But like said above...I bet you would like some of the old stuff I got if you were breakin in your flat tappet cam.

And no please don't PM me to ask to buy any because I have very little old oil left at this point.

IMO the oil I have used don't go bad at 25 years old. That is all.