CF CW on Coolant
Thread Starter
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
CF CW on Coolant
It's time to flush and replace the coolant in my 99.
I'm in central Texas where it almost never drops below 15 Deg. F.
So what's the CF Conventional Wisdom on brand of coolant and the coolant/water mix for my climate?
Thanks.
I'm in central Texas where it almost never drops below 15 Deg. F.
So what's the CF Conventional Wisdom on brand of coolant and the coolant/water mix for my climate?
Thanks.
Acct Suspended APR 2026 by request
Joined: Dec 2010
Posts: 10,367
Likes: 1,271
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
I always use dexcool straight from the dealer 50/50 mix of dexcool and distilled water... I'm sure the prestone dexcool from auto parts stores would work fine but make sure to get the undiluted bottle because you can mix one bottle to a gallon of distilled water and get 2 gallons... if you buy the premixed you are only getting 1 gallon for about the same price, basically you are getting ripped off
Thread Starter
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
Thanks for the comments.
Other posts over the years have suggested that the 50-50 mix will provide freeze protection down to -35F or so (which I don't need) and that more water (like a 25% coolant and 75% water mix) will cool better with sufficient freeze protection down to 0F or so.
Whacha think?
Other posts over the years have suggested that the 50-50 mix will provide freeze protection down to -35F or so (which I don't need) and that more water (like a 25% coolant and 75% water mix) will cool better with sufficient freeze protection down to 0F or so.
Whacha think?
Thread Starter
Le Mans Master
Joined: Aug 2000
Posts: 6,273
Likes: 14
From: Austin TX
You also need to look at the other side of that in that boil over protection is about 265 with a 50/50 mix and it is less with a lesser % of anti-freeze. I don't have access to my charts but I believe it is about 255. While engine overall temp doesn't often get that hot, temps at the boundary point between the coolant and the metal it is trying to cool can easily get that hot.... That's when damage to the metal can occur.
Also better cooling isn't going to happen unless you add something like water wetter. That works well with more water and less anti-freeze but provides marginal help with a 50/50 mix.
Last thing is that corrosion protection is max at 50/50 and lesser at less % anti-freeze.
I live in the high desert of Az where high temps this week have been between 105 and 110 and predicted to be above 110 next week. I still use a 50/50 mix.
Also better cooling isn't going to happen unless you add something like water wetter. That works well with more water and less anti-freeze but provides marginal help with a 50/50 mix.
Last thing is that corrosion protection is max at 50/50 and lesser at less % anti-freeze.
I live in the high desert of Az where high temps this week have been between 105 and 110 and predicted to be above 110 next week. I still use a 50/50 mix.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Most Common Corvette Problems of the Last 20 Years!
Joe Kucinski
5 MOST and 5 LEAST Popular Corvette Model Years in History!
Joe Kucinski
2027 Corvette Buyer's Guide: Everything You Need to Know!
Joe Kucinski
10 Things C8 Corvette Owners Hate (But Won't Tell You)
Joe Kucinski
10 Best Corvettes Coming to Barrett-Jackson Palm Beach 2026!
Brett Foote
Every Corvette Grand Sport Explained! (C2, C4, C6, C7, & C8)
Joe Kucinski
Grand Sport & Grand Sport X Launch Alongside All-New 535hp LS6 V8!
Michael S. Palmer
5 Reasons Bad Drivers Crash & 5 Ways to Avoid a Costly Mistake!
Joe Kucinski
7 Bolt-On Upgrades From Extreme Online Store to Level Up Your C6 Corvette
Pouria Savadkouei
Melting Slicks
Joined: Apr 2009
Posts: 2,479
Likes: 36
Corrosion protection is the other big issue that people often forget. The maximum corrosion protection is achieved using a 50/50 mix of Dexcool and water. Less coolant, less corrosion protection.
For me, I don't take a chance with all aluminum engines. I use a 50/50 mix of Dexcool and distilled water.
Racer
Joined: Oct 2010
Posts: 302
Likes: 2
From: Baton Rouge LA
Le Mans Master
Joined: May 2005
Posts: 6,366
Likes: 249
From: Fort Lauderdale, Florida
I've noticed that too. I'm completely capable of mixing my own coolant. What's the opinion on type of water, tap or distilled? I've read distilled is supposed to be better, then I've read it can be harmful. The shop manual says to use drinkable water. I'm going to be changing mine soon.
Melting Slicks
Joined: Apr 2009
Posts: 2,479
Likes: 36
Or, I've read that you can make it yourself by collecting the condensation from your dehumidifier. Just make sure you're container and condenser coil is clean.
Le Mans Master
Joined: Sep 2003
Posts: 8,847
Likes: 793
From: Longview Texas
Hm, odd. I bought some approx a year ago and it's still listed on Havoline site.
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Always use distilled water if its available. No Chlorine and no minerals. If you had to fill with TAP WATER, its fine but,, distilled is preferable.
BC
BC