oil... 10w30

Oil does not have a shelf life the you would ever outlive. The oil is as good as it was when packaged. The question is whether it meets the SAE service level specification for whatever you are about to put it into. That can be found right on the bottle.

Lugnut

I kinda think about how long it was in the ground before you got it.... The shelf life should still be a couple million years eh....

Mike

"larya" wrote in news:1175286320.132974.295540 @b75g2000hsg.googlegroups.com:

Oh, quite a while.

The lighter fractions will have diffused out through the plastic bottle, but it should still be good.

Problem is, you may have trouble finding an engine that can use that specification of oil. Ten years-old means an SAE "SJ" rating. Nothing newer than model-year 2000 can officially use that grade of oil. And some of those pre-'00 engine specs will recommend 5W-30, not 10W-30.

Most refiners state the shelf life is 3-5 years depending on the storage atmosphere.

Respectfully, they probably state a shelf life in order to buy themselves an exit strategy. At some point you need to be free of liability for a product which hasnt been used.

In fact, in a sealed can or bottle, the functional life could be tens of years...... longer than the application life in many cases.

A couple of quarts? not enough for a whole oil change anyway...and I don't usually mix brands. Use 'em in your lawn mower/tractor, etc...small engines typically contaminate the oil long before the oil deteriorates anyway. I have one mower with lousy rings that gets 2-3 oil changes a year.

A couple of gallons? IMHO OK for a full change in an old beater car...I would check the spec SJ/SF, etc, anyway. Oil is still cheap enough to buy new oil for a car you care about.

If it's a couple of opened, half used containers....dispose of as you would used oil...no idea WHAT is in it, water, etc...

--Don

Don Byrer KJ5KB Radar Tech & Smilin' Commercial Pilot Guy Glider & CFI wannabe kj5kb-at-hotmail.com

"I have slipped the surly bonds of earth; now if I can just land without bending the gear..." "Watch out for those doves..."

I usally get flamed when I state this but the plastic conainers have a certain amount of permeability which allows moisture to enter the bottle; this moisture causes some additives to fall out of suspension and the oil then becomes unusuable. Inspect the bottom of the container for a whitish residue which is a component of the detergent in the oil that has fallen out of suspension.

I certainly wont flame you, but there is very little permeability of water through those plastic containers. Oxygen, to some extent, can penetrate.

But it is a fair comment that, if you see any sedimentation or if the oil is so old that it does not qualify for the specified uses, you might as well dispose of it.

Oxygen atoms combined with hydogen atoms makes water; the permeation is at the atomic level.

For that to happen, you would have to have free hydrogen molecules inside the oil container, which you dont. Hydrogen is so small that, even if you did have a little to begin with, it would have permeated outward long ago.

Oxygen is so much larger that it does not permeate readily, although with time it can diffuse through some elastomers.

Your chemistry and physics just doesnt hold up in this situation, IMO>

To the OP, like Don said, find another use for it. Best to get newer oil with better grading to put in your car. The old is fine for mowers, chainsaws, even some older motorcycles, etc. Oil is inexpensive enough, to get new for the car, if I read the OP post right.

Doesn't hurt to have a quart of that old around for general lubing of hinges, car/house, and other lube needs.

The info I posted is from a "materials preservation" class I took for my work.

Ever find a small packet of desiccant in a product packaged in a plastic container?

Of course. That is enough to take care of atmospheric moisture which may enter when the article is packaged or when the package is occasionally opened. It has a limited lifespan before rejuvenation.

Some of these containers are purged with nitrogen before being sealed.. And the silica give you a little working time.

But it isnt caused by oxygen penetrating the plastic container. Nor is there hydrogen inside most of those packages.