I'm not advocating mixing, all that I am saying is that people have the reason NOT to mix all wrong. It is not that the fluids are physically incompatible like some suggest, but by mixing different coolants you dilute each particular's unique additives and essentially severely shorten either's effective life.

 

That's why I mentioned it. I've never even heard of the "turning into gel" myth. My main concern would be mixing the two and both acting as a double negative to each other making the coolant ineffective down the line, even if the effect isn't instant. Even with the drain intervals and such, I wouldn't mix the two unless i'm desperate.

 

When I was in "coolant school" so I could sell bulk coolant I learned a thing or two.
If you mix Dex-Cool with standard green coolant it WILL turn to a gel, I have seen it, it looked like the gel paint stripper that us lazy people use.

Dex-Cool is a OAT coolant, organic acid technology, notice the word ACID in there?
It has excellent corrosion protection properties IF it is properly maintained.
Dex-Cool IS corrosive IF it is NOT properly maintained, you are actually supposed to check the PH balance once a year, if it is out of range you change it.
Engine coolants never go bad, the additives do.
Engine coolants have lubricating and anti corrosion additives, when those wear out they must be replaced, the easiest way to do this is to change the coolant.
I had a ambulance company that I sold parts washers too as well as bought their used oil.
They would not buy coolant from me because they had a coolant recycle machine, it distilled the coolant, collected it and then added the additives back in.
The only time they needed to buy coolant was if the ambulance blew a radiator hose or a radiator leaked.
Motor oil and gear lube is the same way, the base stock lasts forever, only the additives and viscosity modifiers go bad.
As long as you top off with another OAT coolant you will be fine adding that to Dex.
As long as you top off with a glycol based coolant in a glycol filled system you will be fine.
Just like anything else preventative maintenance is key.
Changing your coolant every 2 years is cheap insurance.
Personally I will not use Dex and I will not recommend it to anyone either.
The GM tech's I sold to even told me that Dex was junk and they do work out of their garages on the side and they dump the Dex as soon as the warranty is up.
There is nothing special about Dex, you can use any aluminum safe coolant.

 

I've mixed dexcool with classic green in a beaker and have not seen any gelling, heated it up too (quite a few have done this experiment over at bob is the oil guy and no one has seen gelling). Universal coolants like prestone are pretty much dexcool. I use classic green and am thinking about switching to g05 though just so I can let it go longer.

 

I did not see how they got it to gel or how long it took to gel but I saw it with my own eyes, a jar with this pinkish orange goo.

And remember that circulating is a cold/hot/cold and years upon years is alot different than a lab.
You can lab test anything, except real world experience.

Bottom line, use whatever you guys want, truth be told any aluminum safe coolant is fine.

 

Spike that is some great info. I had never heard of the gelling before, but I guess it does make sense now that you've explained it.

 

Working in a general auto repair shop, I too have witnessed the aftermath of mixing green with dexcool. NASTY goo!

I run dexcool in mine, and am planning on flushing and refilling with the same later this month as it has been in my system for just under 2 years.

 

i use dexcool. i drain, flush and fill with a gallon of dex and a gallon of distilled water once a year. cost is under $10 and an hour of my time. plus i get to drink beer and tinker.

change anything often enough and it will be clean. my rig is NOT a daily driver but i know what sitting can do to a system as well.

 

Dex sludges when exposed to air, I'm sure people see that and blame it on mixing. Prestone is an OAT coolant with phosphates (or silicates forget which) to make it "universal" you can mix it with green coolant.

 

exactly!

i have seen dexcool gel when exposed to open air. never when mixed in a sealed container mixed with "green coolant".

the rule is just change the coolant often, more often then is needed. if you cant afford the $10 in coolant and hour in time once a year then you should get a different rig as a rover is not for you.