2 Year Old Mixed Dex-cool

[Bowser]

I discovered a gallon of unused Prestone Dex-cool that I had mixed with distilled water in my garage. It's about 2 years old and stored in my garage.

Is this mix still good? I mixed it in the original container and it's been sealed tight.

Bowser

 

[pbm]

I've used something similar with no adverse effects. I'd use it. Remember it's supposed to be good for 5 years in use so sitting in your garage should be no problem.

 

[Ray H]

Ethylene glycol neither deteriorates in storage nor use. (and can be recycled) The organic acid corrosion protection chemistries* in various licensed DEX-COOLs and unlicensed dexclones are also very stable in storage and use. I read on one of the antifreeze websites, Zerex or Peak - can't remember which at the moment - that their DEX-COOL should be considered stable in storage for at least eight years - and, no, that's no indication that there's a hard limit at eight years either. Since your mix has been capped, it's definitely still useable.