changing coolant on 2007 2500HD

[jbres]

Have a question regarding changing coolant on my truck.
(truck is a 2007 gmc sierra 2500HD classic 2wd w. 6.0 gas job)
I had a gift card to Tire Discounters so took my truck there today to get a coolant flush/change. I told them I wanted it changed with something "dex-cool" approved as it states in my owners manual. Guy behind the counter says we use "Valvoline Max Life" which is a universal green antifreeze that mixes with any color and can use on any car or light truck.
Antifreeze I had in my truck was red and still in there from factory with 68,000 miles.

My question is was I wrong with letting them use the "Valvoline Max Life" as a substitute? It technically I guess isn't "dex cool approved" but also is universal, so is confusing me. I am trying to debate whether or not I need to get out the coolant they put in, and make sure to get back in the dex cool. Guy behind the counter actually said he would never use dex cool in any of his vehicles.
Any opinions or suggestions, I am trying to do some preventative maintenance and avoid head gasket failure years from now.
Thanks!

[jus2shy]

GM should be putting out some sort of numerical standard that they have to meet in order for coolant to be compatible. I believe DEX-COOL is a pure OAT style coolant. You really don't want any incompatibility between coolants and I never trusted "Universal" coolants. The main problem with mixing incompatible coolants is getting some form of fallout, namely silica type fallout. This stuff then goes on to clog coolant passages and reduce cooling effectiveness.

Sadly, the coolant market has never been fully standardized like oil. All the car manufacturers have their own standards and color doesn't really mean much in the coolant world either.

I also decided to take a look at the website FAQ for valvoline and they really don't give an answer: "Can you mix Dexcool® with other antifreeze products?
Improper mixing of coolants has the potential to cause corrosion issues. Valvoline recommends using the correct antifreeze/coolant for your particular application."

I personally would dump the coolant if even the website doesn't give an actual answer. I just don't understand why they wouldn't carry the ZEREX Dexcool coolant, since that is dex-cool approved and made by Valvoline.

I'm also almost in the same boat. I want to get some spare anti-freeze to keep in the garage but Mopar went to an all new coolant formulation that has nothing like it on any store shelves. So the current "Grape Juice" coolant costs about 20 bucks a gallon pre-mixed. Waiting for a coolant to come out with a chrysler "MS" standard that matches the coolant. Also, it has been posted never to mix the new "Grape Juice" with the "Orange" coolant that's roughly the same as Dex-cool.

[Passin_Thru]

As long as the Spec #s correlate you can use it. Duramax-Chevy don't require, only recommend theirs. I use Caterpillar and you never drain it. At 300,000 miles you add a bottle of additive and go on. $17/gal. Delo has a 75,000 mile life with no additives.

[Turtle_n_Peeps]

Here's my take on this and it's only my take.

#1. Dexcool it a good coolant. (IMHO)

#2. You don't ever want to let Dexcool exposed to O2 or it will turn into a bad coolant REAL fast.

#3. You don't ever want to mix Dexcool and green.

#4. If you mix Dexcool and green you will get a milkshake of mud in your cooling system.

#5. If you want to change from Dexcool to green you need to really flush the system to make sure there is no more Dexcool left in the system.

#6. If you accidently mix Dexcool with green get that stuff out of your cooling system immediately!!!

And now I will let the people say if any gasket looks at Dexcool it will fail within 2.3 seconds. :B

[MARKW8]

I can't really say it will or won't hurt anything. That said, I would have taken my truck and money elsewhere. Most every manufacturer today has their own mix. There's no way for the average owner to know if it really matters.

Mark

[jbres]

mine says 150,000 or 5 years whichever comes first...

[Cuffs054]

This is a pure WAG but I think GM really wants that orange stuff. Interestly, my owners manual shows change interval at 150K for regular driving.