Exact Antifreeze Brand

[Aurora40]

Originally Posted by Dynomite

Is Prestone Extended Life antifreeze a good selection for the LT5 engine?

In short, no.

Prestone's Extended Life, or "All Makes" coolant is basically a version of Dex-Cool. It is an OAT coolant vs a silicated coolant that was originally spec'd for the LT5.

I could be wrong but I don't believe Prestone makes any silicated EG coolant. The only thing I'd consider is their Low-Tox coolant. It is a silicated coolant like the LT5 came with, but it is made from propylene glycol vs EG. That's what makes it low tox. GM has released TSB's saying PG coolants are fine for use in their cars, but of course they have never done any real certification testing with it.

I run low-tox coolant in my LT5 now. Partly because I can't find any EG silicated coolant, and low-tox I can get locally. Also partly because the car drips coolant sometimes, or at least it has in the past, and I am not a fan of dripping toxins.

[Hammer]

Originally Posted by Dynomite

Thanks ......I see this discussion has been going on for 2-1/2 years with mixed results. Just tell me a brand of coolant I should use and if I can get it at WalMart, Autozone, Kragens

I've kept an eye out at the stores you mentioned and have not found a coolant that meets the 1825M requirement in the brands they carry. The only place I have found the 1825M coolant for our cars is NAPA. Their house brand coolant has the silicates and the 1825M rating. $8.99 a gallon. I have used it in both cars now with no problems with #458 having around 20k miles on it.

[ZR1Vette]

Based on recommendations of several 'LT5 gurus' and Texaco I went with Texaco Anti-Freeze Coolant (aka 'Green Stuff')... it is GM 1825M certified>>>

https://www.cbest.chevron.com/genera...PDS7641156.PDF

Just my choice...

[Hammer]

Originally Posted by Dynomite

I will check NAPA today (between WalMart and Kragens )....thanks Hammer

And thank you for those nice avatars

You're welcome, looks like yours aren't bad either.

[USAFPILOT]

I just had Jiffy Lube flush out the orange dexcool and fill it with their 50/50 green that they use for most all other cars. I thought until after reading this that the green was good and orange dexcool was bad. Anyone got an idea of what exactly I had them put it? I guess I could go ask. I know it isn't dexcool, but I dont know if it is silicated or whatever? At least something fresh is in there for now. We had to run like 40 quarts through it before all the orange stuff was out as well. It took quite a while. Again, all I asked them for was 50/50 regular green antifreeze. But it didn't really look all that green. It was watered down alot. More of a yellowish tint.

[ZR1Vette]

More of a yellowish tint.

That sounds like they put in a product such as Prestone Extended Life which is not GM 1825M approved, but rather GM 6277M spec which makes it DEX COOL compatible (and this is not what the LT5 uses). I go back to Jiffy Lube and ask what they use and if it is what I suggested then you need to replace.

[Aurora40]

As mentioned, NAPA may have silicated coolant. Michael, where do you buy the Texaco stuff? Texaco formulated the Dex-Cool for GM, and has been the maker of other fluids as well (I want to say the original ZF fluid was Texaco oil). I'd trust their brand.

But GM still sells the green silicated stuff. If you want to be 100% positive, this would be the no-risk way to go. And it's available anywhere a GM dealer is. But you will pay for it for sure. I think the last time I bought a gallon it was close to $30 from GM.

Dynomite, I'm not sure there are diverse opinions on anti-freeze? Maybe I have to re-read the thread again, but I believe most everyone feels the originally spec'd coolant is the best way to go.

[Scrrem]

Ok, now that I have a water pump to replace, I have read this entire thread (Whew!!!) and am watching with great interest. It seems like Texaco is the way to go, now the hunt to find some.
Rich

[ZR1Vette]

There are a few remaining Texaco stations in Northern Va... I got the green stuff at a Texaco station in Falls Church area. Since Texaco is now Cheveron/Texaco, Cheveron stations sell a antifreeze which appears to be the Texaco green stuff, but relabeled... now to the "appears" part...I have not confirmed as fact.

[SharkPilot]

I have read through this thread and I'm still not sure about what is safe and what isn't. Okay, I know that Dexcool is a bad idea. So perhaps you guys can take a look at what I'm using and give me some opinions...

Right now I have Peak Long Life 50/50 Prediluted in the cooling system of my '91. The ingredients are: Water (7732-18-5), Ethylene Glycol (107-21-1), Diethylene Glycol (111-46-6), NJTSRN QT1.

Lower down on the label it states: "Meets ASTM D-3306 and ASTM D-4340"

So what does all this mean? The numbers following the ingredients are a mystery to me. What is the "NJTSRN QT1"?
I got this stuff at AutoZone but have also seen it at NAPA stores around here too.

So fire away and let me know what you think.

Thanks, SharkPilot