[cwolf442]

When shopping for Dex-Cool coolant, it seems that there is some mystery about whether or not deionized water is used in the 50/50 premix. I bought some Prestone for GM Vehicles today and started doubting I had the right stuff. There is very little information on the bottle or website.

Taking a closer look on the back of the jug, it lists the ingredients. Water (7732-18-5) is the third one. If you Google the numbers, it leads to a whole other world of scientific data and lab supplies. Long story short, this number is a scientific standard for deionized water! See ThermoFisher data sheet below for CAS 7732-18-5.

So, to those using the GM dealer coolant, bravo! You are taking care of your Volt. To you DIY's like me that are trying to avoid trips to the dealer, check for water (7732-18-5) in your next bottle of Dex-Cool antifreeze. You can be assured that it is also made with deionized water.

 

[MikeBCo]

Incorrect.
That is the CAS number for water. Period. It just so happens that you stumbled onto a product specification for lab grade water, which not too surprisingly contain water; however, that does not mean the CAS number is for this specific grade of water, just that it does indeed contain water.

That being said, I compared the specific conductance (using my homemade, completely unreliable specific conductance test rig - i.e. multimeter) of Prestone DexCool and AC Delco DexCool, and came to the conclusion that the Prestone version is slightly less conductive than the AC Delco version.

 

[cwolf442]

Thanks for the clarification. I'll admit that the CAS world is one that I am not familiar with. Still, it's nice to see a scientific specification on the label.

I also like that you did your own test. Cheers!

 

[hellsop]

The Copious Pile of Bookmarks has this in: CAS Number Search

 

[Danno]

I sent an email to Prestone asking if their Dex-Cool premis was made with deionized water. They never responded.

 

[Steverino]

use their customer service call-in number