[67cruiser]

I hear all the time straight water, another says anti freeze slight fixture, so what is everybody running anyways?? 1967 gto getting ready to try it out, running straight water, im also being told there,s a ceramic coolant out that actually coats the inside of the block, and helps protect the block also, im all ears ,what are you running??

[4dblnkldude]

Wow, I never gave this much thought. I'm running a 70-30 mix with regular prestone, 70% water. I was under the impression that strait water does cool the best but the reason why you put antifreeze in there was to prevent rust. Anti freeze does have a anti rust agent added to it. I'd be interested to hear what others think.

[wytnyt]

using only water isnt good,,,50/50 mix raises the boiling point of your radiator
but running all antifreeze will actually allow it to freeze up in winter

[67blackcherry]

I put Water Wetter in my Firebird and dropped the operating temps 10-12 degrees, I need to dump the antifreeze in the GTO and replace it with Water Wetter, and when my 455 build is done I'll put Water Wetter in the LeMans as well...

[kate`s67gto]

Run 50/50 water antifreeze. I should be able to get away with 60% water and 40% antifreeze. As stated antifreeze does raise the boiling point and provide a good lubricant for the water pump. Water (deionised) is best to use in your system to reduce scaling etc. A 50/50 mix give a -37* freezing point with a 223* boiling point, so by reducing the antifreeze by 10% i should still be safe for storage during the winter months and have a better efficient coolant system .

[cmayna]

My brother use to run 50/50 coolant/water in the 67. When I got the car I did not like the high temp while running the car at a pretty brisk rate or around town, so as I use in my old Mustangs and old Chevy truck, I replaced it with 70/30 distilled water/coolant and a bottle of water wetter.

Now the temp runs at a pretty steady 180-183. Much better.

[Z Code 400]

70% distilled water and 30% coolant. I mix it in a container and pour it in at the correct percentage...Robert

[ClassJ]

Similar here. 70% distilled water, 30% antifreeze. I throw in a bottle or two of water wetter as well. Works great!

[mwritter]

I do 50/50 Prestone and distilled H20, with a bottle of water wetter.

[GOAT8U2]

Distilled water for sure, and about 75/25 mix. Like mentioned, you want antifreeze to up your boiling point, water is 212, way too many GTO's hit that on this board so stay far away from straight water if you have a bunch of stock cooling parts still.

RMI 25 is the most referenced additive for cooling, helps with core build up and reduces temps better than any other. I know a few guys who had to flush the system after a month of use due to it cleaning up the core ( older core though ).

[rotdog]

RMI 25 Can you get that auto parts house?

[scotzz]

what is "water wetter" and where do you get it?

[kate`s67gto]

read this . http://www.redlineoil.com/products_coolant.asp

You should be able to buy water wetter at any parts or speed shop.

[carcollector]

Providing your coolant system is in proper working condition, 70/30 is the way to go. I run 80/20. Less junk to remove later when changing the coolant.
Use only G-05 coolant(Honda, Ford, Mercedes).