My neighbor who passed away had a case of Mobile straight 30W oil in plastic qt containers. They are unopened. Could be 10 or 20 years old I have no idea. Blue with the flying wings on the label. There is a code but not a date that I can read.

Is it OK to use just for my 12 HP mower??

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Still Running Against the Wind

Sealed?..Won't go bad. Cracked or bad seal it can emulsify. (white gel-like)...MBG's (micro-bacterial growth) can also be a concern, but easily seen in looking at 20-yr-old petrolium products.

Crack one open. See what you see. Mix and oil away if it looks good. Just don't taste it. LOL.

Looks, feels, smells like regular oil. Looks OK to me.
Thanks

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Still Running Against the Wind

You should be fine if sealed....

I've still got a couple of cases of Evenrude outboard oil my father bought- these are in the steel cans from the late 1950's or early 1960's. I tried a bottle out two years ago- and it works just fine.

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Lost it all in a boat accident

My father was recently still using motor oil from the old cardboard cylindrical cans.

It won't go "bad" per se, but it doesn't have the additives and meet current motor oil standards that newer cars require. Lawnmower use is probably OK, but I wouldn't put it in my car. And I don't think any modern cars are specified for straight 30 wt. anyway, they are using multi-viscosity oils.

If you happen to have an old Puch motorcycle (Sears sold them in the '50s and '60s with a Sears or Allstate badge), you can put it in the gearbox. You could mix it with your gasoline, too, or put it in the oil tank if it has oil injection, but you'd probably be better served by a modern 2-stroke oil for that.

I'd bet the oil's OK but is it what you should be using in your mower?I'd think that most newer mowers would need detergent blends and maybe a different weight.Take care of your mower so you don't have to pay someone from down south to do it for you.

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Dum vivo cano

I always judge whether old (or new, for that matter) oil is good by whether or not it is still slick.

Slick = good
Not slick = bad

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Georgia On My Mind

It might not be spoiled.....but I still wouldn't drink it

Mobil claims a shelf life of 5 years on an unopened bottle of synthetic oil, about the same for an opened bottle that is kept capped.

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9tenz

Oil has been in the earth for millions of years before it ever sees the light of day-I don't think 4-5 years more (or 30-40 for that matter) is going to make a difference.
That from my Texas A&M geologist sister in law.

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Forum consigliere

A highly refined petroleum product, with MANY complex additives is WAY different from crude oil.

Have you heard of gasoline going bad?

Gasoline is made from crude oil, so it should be good for 4-5 years...right?

Well, it's not. A year, or LESS.

Automotive oil has a shelf life too. The complex molecules, such as the the detergent and multi-viscosity additives, break down over time. Then the oil no longer will lubricate up to it's original specifications.

Five years is the generally accepted length shelf life for oil. I'm sure it's good for longer. Over 10 years, and I wouldn't use it in any engine I own.

Oil is relatively cheap.

Engine repair, or replacement, even for a lawnmower, is very expensive.

Use it for the ram on your reloading press.

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Shoot fast & live long
Warren