Engine oil shelf life

[junaido]

I just changed the oil on my M25. There was a sealed gallon of Delo 40 sitting on the boat left by previous owner, so I used it. Just as was sitting down, congratulating myself on a job well done, I happened to glance at the oil jug. It had a 2001 date printed on it. It seemed to look and pour normally. Seems to be the right consistency and color. My search online shows most companies say 2-5 year shelf life on engine oil. Yet there are many people who report using 15-20 even 30 year old engine oil in their car engines without ill effect. What do you guys think? Should I suck this oil out or just use it? Walmart has Mobil 15W40 for $10.50 right now so I picked some up just in case.

[Ron Hill]

juda : I have never heard of oil having an expiration date when in the sealed can/jug.

My thought

[KWKloeber]

Whew!! What luck.
Conventional oil has been in the ground 60 million years.  If it expires in 5 years we've gotten it out JUST IN TIME.   
What a break.  Imagine what a waste it would have been had it all gone bad just sitting there waiting for us to pump it out!!!!   

Pour a refreshment.
Go sit back down.
Put your feet up.
Re-congratulate yourself.

[Stu Jackson]

Agree, no worries.

[waughoo]

Pour a refreshment.
Go sit back down.
Put your feet up.
Re-congratulate yourself.

I am going to put this away for future use!!  Thanks Ken.

[KeelsonGraham]

Whew!! What luck.
Conventional oil has been in the ground 60 million years.  If it expires in 5 years we've gotten it out JUST IN TIME.  : thumb:  
What a break.  Imagine what a waste it would have been had it all gone bad just sitting there waiting for us to pump it out!!!!   

Pour a refreshment.
Go sit back down.
Put your feet up.
Re-congratulate yourself.

Yup, they just suck it up and bottle it.  . Personally, I'm suspicious of using very old oil that's lain opened for years.

[Catalina007]

You do know the reason they tell you to change your oil every 3,000 miles and shampoo and rinse twice is to sell more oil and shampoo, right?

[Breakin Away]

Sorry guys, I disagree pretty strongly with much of what has been said here. Modern motor oil (even non-synthetic dino oil) does not last forever. It's not the same stuff from 60 million years ago. All modern motor oils have rheology modifiers and detergent additives which can break down and/or flocculate over time, causing a loss of lubricity. This is especially true of multi-grade motor oils (lots of rheology modifiers) and diesel grade motor oils (lots of detergent additives to suspend the high levels of black soot that diesels generate). Sorry, they don't just suck it out of the ground and bottle it without significant modification. I think you're fine up to about 5 years. 20 years is not a great idea. I wouldn't panic over it at this time, but I would make sure to replace it after one season. Google "motor oil shelf life" and you'll see typical shelf life of 2-5 years. They're not trying to scam you - there is real science behind this.

I also inherited some 4-cycle gasoline grade motor oil that the prior owner had apparently used in his dinghy motor. It was in a white bottle. I dumped it because it looked pretty old. Once I got most of the unused oil out of the bottle I looked inside and saw noticeable sediment (easily seen because the bottle was white). I think the additives had flocculated as I described above.

I buy my oil (Rotella T4 15w40) by the gallon and always have some left over from the prior season. I always practice FIFO and use the leftover from last season before cracking open a new bottle.

[Stu Jackson]

>>>>>>>>>>>
>>>>>>>>>>>>>

I buy my oil (Rotella T4 15w40) by the gallon and always have some left over from the prior season. I always practice FIFO and use the leftover from last season before cracking open a new bottle.

That's what I do, too.  Can't imagine having any older than 2-5 years doing it this way.