"Kurt Cypher" <kcypher42.lists@gmail.com> wrote:
> On Tue, Jul 15, 2008 at 4:14 PM, John Dunlap <jsdunlap@roadkill.org> wrote:
>>
>> Hmmmmm,
>>
>> I thought the only thing that broke down motor oil was heat,pressure
>> and contaminants.
> The sources I've been able to find online say that under "ideal
> storage conditions" the shelf-life ranges from 2-5 years. "Ideal
> conditions" appear to exclude high heat & freezing (which puts a lot
> of average home garages outside of ideal).
When you first asked your question, my gut reaction was to say to
just use the stuff (which I ended up doing anyway), it hadn't really
occured to me that oil might have a shelf life, so I did some
searching myself, and probably came across many of the same sources as
yourself. What I find interesting (and annoying) is that the people
who say oil has a shelf life never seem to say WHY it has a shelf
life. Probably because they don't know why, they just heard it
somewhere, and parrot it without thinking or bothering to investigate
further. Who knows, the source for the idea of a shelf life could
have come from a manufacturer or retailer who wanted to sell more
motor oil... There are a lot of these sorts of "facts" out there
which are "facts" only because everybody "knows" they are so, only
because everybody else "knows" it is so, with nobody really knowing
anything. :-)
Anyhoo, I'd certainly be open to the idea of oil having a shelf
life, but the fact that I could not find anybody willing to say WHY it
might have a shelf life is a huge red flag to me. About the closest I
saw anybody come to that is to say that the additives could come out
of solution, but that will happen to brand new oil too, you just shake
the bottle to mix 'em back in there prior to dumping the whole thing
into the engine...
Another possible reason I saw people taking a stab at was the
possibility of condensation, but this should be minimal in a sealed
container, and even if there was a little bit, it'd evaporate and get
burned up in the crankcase pretty quick; motor oil isn't hygroscopic
like brake fluid, so I wouldn't expect the water to mix with it or
change it chemically.
I'd be curious to hear what an authority such as Blackstone would
have to say on the subject. Speaking of which, I suppose you could
send a sample of the oil to them and they could tell you if there's
been any degradation of the additive package and such, though that'd
probably cost you almost as much as what your Dad originally paid for
one of those cases of oil. :-)
--
-Jon-
.- Jon Steiger -- jon@dakota-truck.net or jon@jonsteiger.com -.
| '96 Kolb Firefly, '96 Suzuki Intruder, Miscellaneous Mopars |
`-------------------------------- http://www.jonsteiger.com --'
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