Old engine oil

[dwass]

I have several quarts of unopened oil on my boat that must be 8-10
Years old. Does the oil loose anything just sitting around like that.

[a64pilot]

Most major oil manufacturers recommend a five yr max for storage.
I get suspicious of that number as it aligns with FAA requirements on rubber and other products as well. I think you have to say something and five years isn’t egregious, you can’t say it lasts forever, nothing last forever.
I’d be surprised if there was any actual testing to confirm it.

[Calif.Ted]

If airtight I'd think the only possible degradation could be if some of the additives settled out. I'd shake it up and pour into a clear plastic measuring cup and if it looks like oil it's probably OK.

[Snore]

Math question. 5 quarts of oil <$20 versus engine >$8,000 perhaps >$15,000

So would you risk you engine for the price of a few beers??

[a64pilot]

I don’t think you would be risking anything, and I’d use it if there was no other oil and I needed oil.
But otherwise, why? There just isn’t an upside to this

[travellerw]

I had oil on my boat for 2 years. After 2 years it had very clearly separated. I shook it and it seemed to go back together. However, I didn't trust it so I disposed of it.

[Attikos]

The last time I read an MSDS for motor oil, it said "indefinitely."

[a64pilot]

Originally Posted by Attikos

The last time I read an MSDS for motor oil, it said "indefinitely."

I think that would be for how long is it unhealthy etc.
I know Shell, Chevron and Mobil 1 say five years. I don’t know about others.
However I’d bet that what they are really saying with the five years is that is a number they are comfortable guaranteeing that it will meet all of its specs is all, if stored in freezing cold or really hot container etc, and what else would you expect?

[Calif.Ted]

The attached website addresses the issues of old oil, you'll have to weigh the possibility of contamination based on storage conditions.

It is not unusual for additives to separate in oil. If this happens with a quart sized container of motor oil, it can easily be fixed by shaking the container allowing the content to mix back together.
Be sure to use the entire container to maintain a balanced mixture of oil and additive in the engine.

https://petroleumservicecompany.com/...il-shelf-life/