Coolant Differences:Dexcool vs "Extended Life

[Bill A]

I was comparing Prestone's Dex Cool labeled product with their Extend Life Coolant at the auto parts store the other day.

The ingredients and their percentages appear to be the same.

Anyone know if this is the case?

And if it is OK to use in the Northstar or other GM aluminum engines.

Thanks

Bill

[JimD]

Can't answer your question.

My position is;

Texaco-Havoline developed Dex-Cool to GM/Cadillac Division corrosion inhibitor chemistry additive package specifications. Havoline Dex-Cool is available at Wal-Mart.

Why use another brand?

[JasonA]

Any product (coolant or otherwise) which is acceptable in ANY vehicle is optimal for NO vehicle. Honda, Ford, GM, Chrysler, M-B...all have different coolant chemistry make-ups. It's not like motor oil where everyone pretty much uses the same (API) spec. Coolants are apparently very specific in terms of silicate content and compatability with different metallurgies, etc. Given that the Prestone "yellow" coolant is so generic that it can be made to work in anything, it is, by definition, the optimum blend for nothing.

I would ask Prestone if they've validated that coolant to the GM Dex-Cool spec. Given that they still sell both (Prestone still does), I'd assume not. That in itself is enough answer for me personally.

[Bill A]

My local Wal Mart did not have Havoline the other day and no ID tag on shelf either.

That's what got me looking at the Prestone Extended Life.

[JohnnyG]

I ran into the same predicament when I changed my coolant earlier this month. No Havoline, but plenty of Prestone Extended Life. (50/50 and 100% stuff)

I would ask Prestone if they've validated that coolant to the GM Dex-Cool spec. Given that they still sell both (Prestone still does), I'd assume not. That in itself is enough answer for me personally.

This mixture is orange, just like the factory stuff I removed a few years back, and just like the Texaco product that I put in at that time. I chose to use the 50/50 premix, and it took me exactly 2 gallons to do the job. It states clearly on the label that it meets GM Dexcool requirements and specifications. Just glancing at the ingredients, it appears to have the same corrosion protection chemicals that the guru wrote about a few years ago.

I am now in full support of using the premixed 50/50 stuff. The price is now equivelent to buying the 100% stuff and a gallon of distilled water and mixing your own....without the hassle. I also remember that the Guru stated that it was CRITICAL to maintain EXACTLY 50/50 mixtures of coolant and water when using this corrosion inhibitor package in aluminum block engines. Too little coolant, it goes corrosive, too much does the same thing. Also a BIG reason to avoid water flushes of any kind in a Northstar...throws your final mixture percentages off.

[JasonA]

This mixture is orange, just like the factory stuff I removed a few years back, and just like the Texaco product that I put in at that time. I chose to use the 50/50 premix, and it took me exactly 2 gallons to do the job. It states clearly on the label that it meets GM Dexcool requirements and specifications. Just glancing at the ingredients, it appears to have the same corrosion protection chemicals that the guru wrote about a few years ago.

Yes, Prestone DOES make a Dex-Cool coolant. And it is orange. I've used it before myself.

And that's what I was saying. Prestone does sell a Dex-Cool coolant. They also sell a generic extended life coolant (the yellow stuff). The original poster was comparing the two. I was surmising that since Prestone DOES sell a specific Dex-Cool coolant, I'd say that their yellow coolant does not meet GM's Dex-Cool spec, and I wouldn't use it. But the Prestone Dex-Cool -- yes.

[Ranger]

I also remember that the Guru stated that it was CRITICAL to maintain EXACTLY 50/50 mixtures of coolant and water when using this corrosion inhibitor package in aluminum block engines. Too little coolant, it goes corrosive, too much does the same thing.

Johnny, that does not sound right. PH can't go both ways. Besides, I think they even give you freeze protection numbers for 60/40. Not saying 50/50 is wrong. I just can't imagine it being THAT critical and doing damage it you are off a bit.

[KHE]

I also remember that the Guru stated that it was CRITICAL to maintain EXACTLY 50/50 mixtures of coolant and water when using this corrosion inhibitor package in aluminum block engines. Too little coolant, it goes corrosive, too much does the same thing.

Johnny, that does not sound right. PH can't go both ways. Besides, I think they even give you freeze protection numbers for 60/40. Not saying 50/50 is wrong. I just can't imagine it being THAT critical and doing damage it you are off a bit.

I remember the guru saying that it was critical to have the mix 50/50. Not that a little off one way or the other would hurt anything but DexCool is never to be mixed at concentrations greater than 60/40.

[BodybyFisher]

I also remember that the Guru stated that it was CRITICAL to maintain EXACTLY 50/50 mixtures of coolant and water when using this corrosion inhibitor package in aluminum block engines. Too little coolant, it goes corrosive, too much does the same thing.

Johnny, that does not sound right. PH can't go both ways. Besides, I think they even give you freeze protection numbers for 60/40. Not saying 50/50 is wrong. I just can't imagine it being THAT critical and doing damage it you are off a bit.

I remember the guru saying that it was critical to have the mix 50/50. Not that a little off one way or the other would hurt anything but DexCool is never to be mixed at concentrations greater than 60/40.

I recall this also

[Bill A]

I talked to Prestone tech support today.

They say the Ext Life is OK for aluminum GM engines or any car. Meets or exceeds ASTM D3306 & D4985

I asked if it was exact same specs as Prestones DEX COOL approved product.

They would not confirm or deny it.

I suspect for one thing Prestone has to pay GM handsomely to use the words DEX COOL on their label. They may not be able to claim the Ext life is same thing even if it is or quote the GM spec numbers on unlicensed product.

I would think GM's propietory use patent on the DEX COOL has expired by now so Ext Life COULD be the exact same thing but yellow not orange.

I found some Havoline DEX COOL today so in it goes. It meets or exceeds ASTM D3306 and GM6277M specs as does the Prestone DEX COOL approved stuff. The Prestone Ext Life does not mention GM6277M spec on the label.

The missing link is what the GM specs are.

Only a scientist or lawyer may ever know for sure.

Bill A

[JasonA]

If GM6277M is the GM Dex-Cool spec, and the Prestone yellow Extended Life doesn't list it, and their tech support won't confirm it, I think we do know for sure. Again, different coolants from different manufacturers are very different. GM's Dex-Cool is a full-on OAT, or Organic Acid Technology, coolant. Chrysler uses a HOAT, or Hybrid Organic Acid Technology, coolant. Ford and Honda use something similar to Chrysler I believe, but it's not the same. In addition, Ford uses (or used to use) different coolants in its Powerstroke engines vs. its gasoline engines.

All this follows what we know to be true about the relationship between OE and aftermarket. OE specs are often very particular and very specialized in terms of application and use. The aftermarket tries to save money and lure prospective buyers with a "one size fits all" type of part, or application.

Both the Havoline and Prestone Dex-Cool coolants should be 100% good to go. They are designed for the purpose and apparently pass the GM6277M specification. The fact that Prestone was pretty mum regarding the relationship between their yellow coolant and Dex-Cool tells me all I need to know (personally).

[Texas Jim]

If GM6277M is the GM Dex-Cool spec, and the Prestone yellow Extended Life doesn't list it, and their tech support won't confirm it, I think we do know for sure.

Both the Havoline and Prestone Dex-Cool coolants should be 100% good to go. They are designed for the purpose and apparently pass the GM6277M specification. The fact that Prestone was pretty mum regarding the relationship between their yellow coolant and Dex-Cool tells me all I need to know (personally).

Agree totally. If it ain't "Dex-Cool", it ain't going in "MY" Cadillac.