I tried searching for the answer to this question but couldn't really find a direct answer. I don't know if there is one but, I was wondering for an aluminum ls1 engine like I have in my car, what is the best rad fluid that I should be using? Does it matter what color it is? Thanks for all suggestions or answers.

well i've always used the regular green PEAK 50/50 antifreeze but the LS1 probably takes dexcool antifreeze (the orange-red stuff)

If you don't know if you're supposed to be using red or green, go for the Prestone stuff that blends with all types of anti-freeze. Its a no-lose situation.

dex cool (orange crap) is useless imo it dose more harm than good if u don't change it every year it will gum up and mess your radiator up i had that happen with my s-10 now i just run geen stuff works fine

if u left gallon of dex cool in a garage for 2 months it will gel up ...... think about that if your car is stored in winter lol :/

Cool. I've heard arguments on both sides...for and against dex cool. Thanks for the replies

I have a two yr. old dex cool jug in my shed. Not gelled. Not saying it's the best, I'm just calling BS

I think Prestone is good. What color should you use for the thirdgen's? Green right?

plain water cools better than anything else


dont really need much antifreeze with it being warm enough for the year now


every vehicle i have seen with dexcool has rusted crappy looking fluid - including my 88 toyota and the 95 grand am

for some reason it causes the iron to rust badly, nasty


seen some horrible ones over the years


never seems to happen with the regular old green stuff, extremely rare.

all i ever trust is a little green antifreeze along with tons of water about 30/70 or 20/80 green to water, never nay cooling issues at all and ive had a billion years makes and models fromt he 50s to 90s over the years, trucks vans., 1 tons, 2 tons, you name it ive probably owned one





good luck