[Achelis]

A older friend recently gave me several cases of oil that he'd stored in his hanger 'forever'. Some of the 'ENCO' cans are all metal; the Shell is fiberboard. All have a round-top that used a spout to disperse.

The 3 types are:
-> ENCO aviation oil 120 (mineral oil for break-in?)
-> ENCO Aviation oil E-120 (as above but with additive package... still recommended for an IO-360?)
-> Aeroshell 'W' Grade 100 SAE 50 (same straight grade Aeroshell as available today; but with older can?)

I don't want to use oil that's been replaced with 'modern' oil that has an improved additive package; and maybe a petroleum engineer can address what happens when a can of oil sits in a hangar for a few decades (separation?) - but neither to I want to discriminate against a usable product simply because of older packaging.

Thanks is advance to all of those who know so much more on the subject than I do

 

[WenEng]

I would not use the oil....

When I was at Sun n Fun this year buying a couple cases of Aeroshell from the Shell booth, I asked what the shelf life was. Shell told me 4 years after which it would have to be retested. My engine and plane are too important to me questionable oil in it and I would never feel comfortable trying to use it regardless of the deal I got. For me, we're talking lawn mower oil, maybe. Or, flush out oil. But, thats just me. Call Shell or visit their website..
Here is some info from their web site about shelf life and re testing..

http://s01.static-shell.com/content...tion/downloads/pdf/products/all-shelflife.pdf

 

[Achelis]

The Experts at Blackstone Labs Say...

There is no question but that Shell recommends retesting oil after 4 years storage; however when I spoke with Blackstone labs (who have been testing my oil for 15+ years) I got a different story. Blackstone bought several quarts of vintage automotive oil on eBay and it met all applicable specifications. They further said that so long as the containers are sound and leak free, the oil should be fine. A damaged container might lead to oxidation, and it would be wise to pour a quart into a glass jar looking for striations or separation... but if the oil looked like oil and was odor free go ahead and use it. I've decided to fly about 10 hours and drain and test to confirm that by being cheap I'm not risking damage to the engine.