Shelf life of unopened synthetic "racing" engine oil?

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BradH
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Shelf life of unopened synthetic "racing" engine oil?

Post by BradH »

I did some generic searching for "shelf life of synthetic motor oil", since I have more than a case of "good stuff" that's at least 10 years old sitting on the shelf in my climate-controlled basement. FWIW, I define "good stuff" as having cost me about $10 (or more) per quart.

Some manufacturers (Amsoil, Mobil 1, Castrol, ...) say five (5) years... which makes me suspect since they certainly would prefer consumers purchasing new product over not. :lol:

Some people have stated as long as it's not been opened nor exposed to extreme heat or cold that there's nothing to "go bad", other than there may be some additives that come out of suspension during extended storage. "Shake it up and pour it in!"

Any feedback or input on the subject is appreciated, given I'm not a tribologist.
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by Racing68 »

I had some leftover VP racing fuels synthetic gear lube on the shelf for probably 10-12 years, I think it was what some Prostock cars were using at the time. Decided to use it in a gear reduction case that I was changing the lube in. Well, the chunks kept most of it from going in the case saving some cleanup time.
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by DracerX »

I'm interested in the answers here too as I also have some decent oil sitting for a bit.
I've thought of turning the cases upside down every now and then to help with the "settling".
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by rebelyell »

it's too old; when should I stop by to dispose of it for ya? :roll:
lefty o
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by lefty o »

ive been told by a guy in the oil industry that over time, the additive package in oils will fall out of suspension. how long does it take, i dont know.
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by Roundybout »

Just my own experience, I had the same situation with a couple cases of Penzoil that were more than 10 years old. Only reason I noticed was you could clearly see whatever was in suspension settled on the bottom in the yellow bottles. Ended up recycling it.
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by dannobee »

I had this discussion with Peter Filice of Red Line Oil years ago. He recommended putting half of the bottle in the engine, then shaking up the remainder before putting that half in. And he was pretty adamant that the "good stuff" settled to the bottom.
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by David Redszus »

Roundybout wrote: Tue Feb 16, 2021 7:35 pm Just my own experience, I had the same situation with a couple cases of Penzoil that were more than 10 years old. Only reason I noticed was you could clearly see whatever was in suspension settled on the bottom in the yellow bottles. Ended up recycling it.
For given performance level, fresh oil is better than vintage oil. Over time, mfgs have continuosly improved the
additive packages.

If the additive package drops out of the oil, the oil is junk.
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by digger »

David Redszus wrote: Tue Feb 16, 2021 9:22 pm
If the additive package drops out of the oil, the oil is junk.
don't you just shake it a bit to mix it back in?
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by hoffman900 »

digger wrote: Tue Feb 16, 2021 10:01 pm
David Redszus wrote: Tue Feb 16, 2021 9:22 pm
If the additive package drops out of the oil, the oil is junk.
don't you just shake it a bit to mix it back in?
It’s not paint :shock:
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by induction apprentice »

Interesting. Sub conciously I often shake the oil bottle prior to opening and pouring. I guess because years ago I thought incase any of the chem pack settles. I had better give it a shake. Been doing it ever since. But after reading this post. I won't any more. From now on I will look in the bottle after I pour and then think it through if i see any seperation. I wonder that if this is the case. Why doesn't sae or api mandate an expiry date or expected shelf life label.
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by induction apprentice »

I am now wondering if I have seen oil bottles date stamped in the past?
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by ProPower engines »

I was told years ago when we were sponsored by some oil companies that the race oil should be turned to keep from settling out the good stuff to one end of the bottle.
We always rotated cases upside down for a month then turned them back over during the off season.
Makes sense the additives will separate to the bottom over time but will come back the other way with time.
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by David Redszus »

While an additive normally exists in the dissolved state inside the oil, there are mechanisms in
which it could come out of solution and cause problems.

Additives can lose their solubility and transition to a suspended state in a lubricant for a variety
of reasons. Heavier additives, such as solid extreme-pressure additives, foam inhibitors and some
anti-wear additives, can simply separate due to extended storage times.

While it is uncommon for antioxidants to separate quickly due to storage conditions, it is worth noting
that the less controlled the environment in which the oil is stored, the quicker the additives will separate.

Engine oils have the shortest shelf life due to the heavy additive load they carry and thus should be
used as quickly as possible to mitigate any problems associated with separation.

Contamination can also cause additive precipitation. Most additives in lubricants are polar
by nature, which means they have an affinity for other polar objects. A precipitate will form and
drop out of the oil because it is no longer soluble.

Contaminants such as dirt, moisture and wear metal are polar as well, so they attract
additives. As additives build up on contaminants, they begin to settle out or are separated
by filters. This removes the additive from the oil and impacts the health of the lubricant.

Some additives are filtered out due to their size. This is a problem that occurs mostly
with anti-foam agents, as they are larger and often suspended rather than dissolved in oil.
If the filter's pore size is too restrictive, it can lead to additive buildup on the filter's surface,
thus removing additives from the bulk of the oil.

In addition, as the oil flow changes pressure and temperature, it can affect the solubility of
the additives and some contaminants. In this case, as oil flows through the venturi, it
experiences a drop in pressure. This rapid change in pressure may be enough to cause some of the
dissolved additives to come out of solution and precipitate on the machine surface and in the filter.

This can be observed in some varnish-removal methods in which oil is stressed in a similar fashion
to force varnish precursors to come out of solution, allowing them to be filtered and removed.
from Machinery Lubrication magazine

Each bottle of oil has a printed product batch code visible only after very careful examination.
The code reveals the manufacturing batch and date of production.

Speaking of oil bottles, many are subject to paneling, which is a distortion of bottle shape
due to absorption of an oil component by the plastic bottle material. Bottle materials are porous
and will allow the escape of light fractions and permit oil oxidation as well. A reduction in oil
solvency may cause an additive dropout.
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Re: Shelf life of unopened synthetic "racing" engine oil?

Post by BradH »

Guess this will teach me not to stockpile oil before the car ends up apart for a far longer than expected time.
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