Lately with the number of people reporting overheating problems the general recommendation for the coolant replacement is Dexcool. Can someone please explain to me exactly why "only Dexcool" should be used.

Yes, I understand that GM recommends Dexcool - but I fail to see what the magical qualities are of Dexcool in relationship to the cooling capabilities vrs "regular" antifreeze.

Both have rust inhibitors, water pump lubricants, and cooling abilities etc..

What am I missing in this?

 

The metallurgy if the Ecotec engine, the heat up and cooling off times of Dexcool, the computer parameters set by the engine designers, in this case Aston Martin, along with Saab.
The shelf live is longer with a recommended life of 5 years in the engine as opposed to 2 years for the green stuff.
Now I don’t recommend to use Dexcool in an engine not designed for it, because of the same reasons.
I thought it would be a great idea to use Dexcool in my last pickup truck a 1988, inna brand new crate engine from GM a 355 SBC, however GM informs do to use good old green in a 50/50 mix with water. So that’s what I did, an the kid I sold it to still changes the coolant every 2 years like clock work and uses the recommended 190 degree thermostat.

My point is why try to reinvent or out think the engineering staff that got paid a whole lot more then I do to come up with a longer lasting combination

 

Just my opinion.
All I've ever read is that Dexcool was created as an environmentally "safe" replacement for regular antifreeze or ethyl glycol. (sp?)
Does Dexcool work better for cooling ? Not that I've read about. But there are stories of it turning acidic when exposed to air. Acid in a cooling system......well, you can figure that's not good.
One thing to note is Dexcool and regular antifreeze are NOT compatible. Do not mix them together. Mixed together they will form clumping in the coolant and turn it to a brown milky sludge that will coat the inner cooling system.

Bottom line is that GM recommends Dexcool for our little cars. I'll stick with what they say.

 

Found this article, make your own assumption:
https://www.getahelmet.com/jeeps/maint/dexcool/

 

I think the dexcool stigma is from when it was FIRST formulated. The type that is made now, and came in the HHR, is not as volatile, and is almost an entirely different coolant than when it was first made.

 

And the engines that they put it in that were not designed for it.

Does anyone remember Prestone? The sealer that was too good at it's job, turned out that the newer cars had smaller coolant passages that the chemicals thought were holes that needed plugging.

 

Interesting discussion - thanks all.

I also came across this article that I thought had some good points:
https://www.motor.com/magazine-summa...-or-orange-or/