Does anyone know the shelf life of Mystery Oil?  I’ve had for about 4 years now and am hestitant to use in case it has broken down or degraded. Adding to engine oil
Thx much in advance

According to the 2009 MSDS, assuming the container is tightly closed and properly stored, it has a shelf life of at least 3 years.  If the container’’s never been opened, and not subjected to extreme heat, my guess would be that the shelf life would be indefinite—decades, maybe centuries—and after 4 years the stuff should be fine.

I had some “Marvel Lubricating Oil” (MM005, MMO sold in a 4-ounce can) which I slowly but surely used over a period of around 30 years.  I didn’t notice any change in the stuff.  And that can had a fair bit of air in it as it got near empty.  In storage it got over 90F occasionally.

When Marvel Mystery Oil is tightly closed and properly stored, it can last an indefinite period of time.  A simple way to check if it is still good, is to pour it into a clean, clear plastic bottle.  If the solution is still red and clear, it is OK.  Also, check to make sure there is not dirt or deposits in the bottom of the can.  If this is also clean, then there is no problem at all with using the Marvel Mystery Oil.

My father has a few of the metal qt cans, which in my estimation are close to 15-20 years old.  The MMO inside of those cans is perfect, nothing settled out, it looks exactly the same as what is in the plastic containers.  I would use it without hesitation!

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