oil shelf life - who knows ?

[BobJohnson]

So, just bought 2 gals of oil for my oil change next week. Got me thinking... Each of my engines takes around 3 + quarts of oil. So, after last years spring oil change, I had about 2 quarts of oil unused that I kept in the gallon container for possible top offs during the summer (never needed).

So, now, after next week, I will have the 2 old unused quarts and 2 new unused quarts. This 4 quarts, would give me enough oil to do a oil change on 1 engine next spring (2018).

How long does unused oil stay "good" ? does it deteriorate over time? Was not kept in a climate controlled space at all (deck box all summer and winter).

I have Rotax engines and use a semi synthetic blend oil. But, this question is really in general I guess.

 

[DieselCamel]

I would say As long as the caps have been on and no water or dirt has gotten in the bottles, the oil is good

 

[Alex AZ]

Oil doesn't go bad without contamination, mineral oil will start breaking down after a number of years but definitely not after a couple of years. Think about it this way, the engine oil you buy in store might have been there for a year or so + who knows how long from when it was manufactured until it hit the store. I'd say you go ahead and use it without any concern, I do that all the time on my cars

 

[VONCE]

Yeah I wouldn't even think twice about using it. You're fine. I sold car parts for quite a few years, but I'm not claiming to be an expert on oils and the way they do or don't collect moisture (but I do know brake fluid is hygroscopic!). I assume any moisture collected in the bottle of oil would be very minimal, and it would not mix with the oil. Even if it did make it to the crankcase, it would burn (steam) off the first time you brought the engine up to temp. I've used oil way older than that and I've never seen any adverse affects. But this is coming from the guy who goes 10,000 miles between Mobil 1 oil changes because Mobil 1 says I can (15k if you use their extended performance!), so I don't really think twice about oil and filters. As long as it's in the engine and changed at the required intervals, it all should do the same thing - even if it's a few years old.