Does Oil Have a Shelf Life

[66skylane]

I have an opportunity to get a few cases of 10-15 year old Aeroshell 15w-50. Any concerns with oil this old? Does it degrade with time? I don't want to risk damage to my $30k engine just to save a few bucks. I could always mix in a couple quarts of the old oil with newer stuff? What are your thoughts? Thanks.

[bush master]

http://www-static.shell.com/static/avia ... lflife.pdf http://www.bobistheoilguy.com/forums/ub ... er=1590284

maybe this will help

[dogpilot]

Another article on the subject. It boils down to about 5 years to be safe:

http://www.amsoil.com/articlespr/2007/article_tulsarama.aspx

[qmdv]

It boils down to about 5 years to be safe:

Is that in the can or in the crankcase.

Tim

[Cary]

After reading the Shell link, I had the thought that by the time you shipped off a quart of oil to Shell and they tested it, it would probably be cheaper to just buy new oil.

Cary

[66skylane]

I read all the above articles plus some other stuff I found on the internet. I can't really find anything solid but from what I read I would only use 1 or 2 quarts at a time (after stirring up really good) and the balance new oil. It doesn't sound like this would be harmfull but it does sound like it could be less than ideal to run straight 10 year old oil. I can get 4 cases of this stuff but it will have to be VERY cheap. The guy who has it used to own a FBO and may want to use it as partial trading stock on a straight 1969 F100 4x4 I have hanging around.

[dogpilot]

It is not exactly a simple question or answer. Much has to do with the storage environment, too hot or too cold. Then there is the oil formulation. In and of itself the, the hydrocarbon oil molecules do not seem to degrade on their own. What does cause them to degrade is oxygen, causing oxidation. So sealed containers should keep air out for a reasonable amount of time. The other is what additives may be in the oil. Certain metallic compounds react with the oil over long periods and act as a catalyst. Agitation would enhance the reaction, so storage in a calm undisturbed state would make it last longer.

Turbine oils defiantly go rancid. They are derived from natural vegetable sources. The best oils still are the ones from whales. Finest oils for lubrication we have yet to find. There are no substitutes for some applications, like über expensive watches. So give that poser Rolex wearing twit a knock or two in supporting whale hunting.

Once spent a long flight across the ocean with a Shell lubrication engineer. Asked him a bunch of questions about oils, since 'which' oil is nearly a question of religious proportions. His read on the subject is, all new modern oils are as good as any, either synthetic or dino for the first 3,500 miles/50 hours. The biggest issue is not lubrication but dispersion. They all lubricate as well, but they all start to fail on dispersion of blow by components. Modern fuels now have different components in them to achieve higher octane. These do not disperse and change the pH of your oil over time. The majority of oils do not have buffers in them. Most diesel oils do, as does Aeroshell + (for Lycomings, instead of their magic additive). So bottom line from him; change it frequently and it does not matter what you use.

[GumpAir]

Let's see.....

$30K for an engine.

Oil is $60, $70, maybe $80 a case. Saving chump change is gonna get you what?

Gump

[low rider]

It boils down to about 5 years to be safe:

Is that in the can or in the crankcase.

Tim

Thats pretty funny....I have had a honda snowbwer for 12 years, run hard put away wet .changed the oil , maybe twice......dont get me wrong i change the oil in the plane alot more but............

[qmdv]

It boils down to about 5 years to be safe:

Is that in the can or in the crankcase.

Tim

Thats pretty funny....I have had a honda snowbwer for 12 years, run hard put away wet .changed the oil , maybe twice......dont get me wrong i change the oil in the plane alot more but............

Around 1975 my dad bought a 1937 Ford coupe with V8 60 in it that had only 42K miles. Had not run in 10 or so years. Cleaned up the carb and it started right up. Changed the oil after we put on 500 miles. But that was a Ford.

Tim

[dogpilot]

Guys, did the 37 ford become a daily driver? I put about 12 hours a year on my snowblower. Do either run at 75% rated power for the majority of their running life? Most Honda engines would run with urine as the lubricant for a while.

It doesn't take much to make your engine fail. Personally I have had three radials fail on me (oil could never go old in one, never stays in them long enough), one turbine blow up, a bunch of others get shut down because they where just about to fail. Heck you can even clean your old oil. Put the dirty oil in a big container on top of a chair, put another below it twist a rag and put it in the dirty oil on top, and run it over the side so it hangs below the upper container and let the oil drip out from one through the other, wicking through the rag. It will be crystal clear, use that oil and save some more money. Would you do that? It does work, I've seen folks do it in places that find dominos a fascinating and consuming game. I don't fly on their planes or let their doctors come near me with knives.

[oldtech]

I've used some pretty old oil and never had a concern, or a problem. The additive package is constantly changing (improving??), and I think the greatest change is going to be the rating - from sj to SN for example, not because of ageing. I've got farm equipment that han't had an oil change in many years. Mind you... I don't fly my loader.

[L-19]

..snip... Heck you can even clean your old oil. Put the dirty oil in a big container on top of a chair, put another below it twist a rag and put it in the dirty oil on top, and run it over the side so it hangs below the upper container and let the oil drip out from one through the other, wicking through the rag. It will be crystal clear, use that oil and save some more money. Would you do that? It does work, I've seen folks do it in places that find dominos a fascinating and consuming game. I don't fly on their planes or let their doctors come near me with knives.

I'm going to have to try this with my used Aeroshell! Sounds like it would make great oil for my old lawn mower!

[flyingzebra]

Since it sounds like it's part of a deal on your truck, how about taking it and just using it in anything but your airplane? Maybe mowers or tractors? Its probably great oil but if the grass stops getting cut it's a much smaller deal than if the big pilot cooler fan stops.

[mtv]

Old time mechanic to me some forty years ago: "Oil is the cheapest thig you'll ever put in an airplane."

On the other hand, Aeroshell is pretty stable stuff. I seriously doubt it would harm anything.

Then again, read advice above.

Put it on eBay with full disclosure if you're not comfortable putting it in your plane.

MTV