Jeep, I would question this, as ALL oils are a combination of different things, I have to think(unfortunately) that all things have a shelf life
as there blended together in the process of making,m HOW Long will it take for maybe things to separate??
I have NO clue
and once a motor is run, its mixing both things in the oil itself and wear and tear parts from motor into oil
ever open up a motor that sat for yrs and yrs and find all that THICK crap on the bottom??
as things settle from USED oil and time passes, it changes the make up of the oil(as does again the mixing of micro metal parts from wear and tear into the oil)
so, I still say TIME alone effect s oil
an air tight what ever will still be prone to condensation, one that has air flowing will actually have lower odds of it, as air flowing helps it evaporate rather than building up!
I doubt anything is a worry in a few yrs like deal, heck oil in a can in a place that vented well, should last a LONG time
but if I had the choice to use brand new oil over 50 yr oil of same weight, I know what one I want in my motors LOL
just think about ALL the differences in oils , due to so many different brands made, SLIGHT differences I give, but little things matter ?? NO ??
Well obviously advances have been made in oils in the last 50 years, so completely agree with you there.
As far as time in and of itself affecting oil...it's millions of years old
. Bottled oil is purified, and has additives put in. Then it's sealed. That keeps moisture and contaminants out, so I'm sticking with my "oil sitting unused in a climate controlled environment doesn't age"
I agree, you run an engine, crap gets in the oil, and that crap isn't good for the oil or the engine, but in an engine that isn't run, pouring oil in there is no different that oil sitting in a bottle; it will not "go bad"
I also disagree with you on the "air-tight being more prone to condensation". If it's air tight, there is a set amount of moisture in there. That is ALL that can get in there. In an open to air system, everytime you have a fog, you have new/more moisture introduced to the system.
Opening up an engine that has sat for years and years and seeing crap come out isn't the oil, it's the byproducts of running an engine.
We have a 1985 Jeep with 4600 miles on it. I change the oil about every 200-300 miles, or about every 3-4 times it's driven. Sometimes it goes years without being changed, because it just isn't driven much. The oil coming out after several years looks just like the oil going in (enough for me to think "Crap, I'm wasting good oil here"). I change it because oil changes are cheap and I want to make sure that moisture from condensation doesn't accumulate in the engine, but honestly I think I'm wasting oil, time, and money changing it as frequently as I do.