Old new stock oil and trans fluid

[DC Concours]

While doing some cleaning in my basement, I came across 5 gallons of unopened 10w40 dino castrol motor oil. These are  over a decade old. Maybe 12 years old. I also found 2 gals of unopened Valvoline synthetic transmission fluid. There were also 2 open gals. One of oil and one of trans fluid.

Everything looks nice. The opened trans fluid seems to have fluid separation but once mixed it became uniform.

Are any of these gallons usable? What is the shelf life of motor oil and transmission fluids?

 

[maxtog]

I don't know about transmission fluid, might depend on type?

But as for sealed motor oil, synthetic or not, I don't think it matters how old it is, as long as it is sealed air-tight and not stored in extreme temps (freezing cold/boiling hot).

[VirginiaJim]

Anything open, I would discard.  Also, depending on the age they may or may not be still suitable for a vehicle so check the specs on the unopened stuff.  If it's oil for your C10 I would think the 10w40 stuff should be fine as long as it's MC oil spec'd...ie more zinc.  Although I've heard that some of the more die hard C10 owners have run cooking oils at times...

[DC Concours]

Thanks. I wont use the opened bottles.

How do I know what has more zinc? Can I put a zinc multivitamin in it and call it a day? Like the one I use to fend off colds.

[VirginiaJim]

Interesting point.    If it's mc specific I would think it would have the zinc.  If not, most likely it doesn't.  Other's might chime in on that, though.