96_LT1

As above, does it have to be distilled, or can i use tap water? Im refilling the coolant back up!

Thank you

Fozzy_Bear

Each area has different minerals in their tap water. If you have a lot of calcium (IIRC there is one other 'bad' mineral too) in your water, it will build up and can clog your radiator. If you know for a fact that your water supply is low in calcium, then you may be OK using it.

Considering the average price of a gallon of distilled water, it's usually not worth the risk.

Corvette Kid

You should use only distilled water.

RAGOVET

Distilled only... or get the 50/50 premix that Prestone sells.

Mr. Peabody

Iron in the water is really bad also.

artvette

Agree!

c4cruiser

Distilled water typically runs less than a dollar a gallon at grocery stores so it's well worth the extra trip to the store to get 3 or 4 gallons (you need two gallons of water and 2 gallons of Dex-Cool to make a 50-50 mix). And most water supplies while fit to drink, will still have some minerals in it. Iron is not a good thing to introduce into the cooling system.

Also,when you refill the expansion tank after removing the old coolant and cleaning the tank, you will need about a half-gallon of the mix to put in there. So make up a gallon of the mix for that and have a jug stored in the garage to keep as needed for any refills.

Aquaman92

I buy prestones 50/50 mix couldn't be any easier.

corvetteronw

Maybe I am wrong but I thought DexCool was already premixed. If you add distilled water to it then it will be too diluted.

TorchRedlt4man

The Dexcool is not premixed. It is 100% antifreeze.

I use the distilled water. Cheap insurance for a very expensive cooling system.

larryfs

I've been using tap water for 30 years, and never had a problem. and I know I have hard water where I live.

F1Fan

also nothing but tap water ever, and no problems.

Nathan Plemons

I've never known anybody to actually put distilled water in a car, never known anybody to actually have problems with the cooling system either. It's kinda a CYA thing on the part of the manufacturer and the anti-freeze maker. Because they can't guarantee the quality of your local water supply, they specify only distilled water.

Bowling Green happens to have very good water that never causes problems. Now if I had to fill my coolant somewhere else, say Crossville, TN. There is no way in hell I'd used tap water.

artvette

Everybody has their opinion. The fact is, that distilled water has less dissolved contaminents in it than any tap water. Whether or not it's worth the small extra cost to use it (depending on how you feel about the water quality in your area, or how much you baby your ride) is up to you. Personally, I would never use tap water in my ride, the same as I would never use anything but the best car care products on the exterior.

wake

I use nothing but distilled water... I've lived in areas with mostly hard water and have seen the insides of radiatiors on cars that had regular tap water run though them...

At $.60 / gallon, it's cheap insurance IMO...

runner140*

You can the the mineral build up on internal parts could be substantial. Go to a supermarket or Walmart and get distilled, its cheap as hell.

Gooseit

I had hard well water for a few years and I used it in my car and it clogged the radiator up, that is when I cleaned to use only distilled water.

AORoads

For those who don't use distilled water, then why not put tap water in your battery (if it's not the sealed type)??? Put it in your iron, too.

Considering the cost of a radiator now that most are made with plastic end caps, and crappy tubing, etc., and considering that if you keep the car long enough you'll probalby have to replace the radiator, why shorten the length of life? We're not talking $10 or $15 radiators here, are we? And distilled water, for all that you're going to use is what---a grand total of $5???

For a few bucks over the past July 4th weekend, it just makes life (your car's life, that is) a little easier. And yes I did read about the "soft water of Bowling Green" and the "30 years never had a problem". My hat goes off to you both.

Me? I never had a problem either in 30 years, and I've never replaced a radiator, too. And I've probably spent a whopping $25 in that entire time on distilled water (remember, distilled water, like everything else, used to be a lot cheaper). Which is far less than a tank of gas for my Corvette, today.

rocco16

I've owned cars and used tap water in both the cooling systems for 40 years and never had a radiator problem. (I also use a radiator flush when I change coolant, however.)

That said, the last time I changed coolant in my DD VW, I used distilled water...and will do the same when I change coolant in the Vette next month.

As some of you have said, "At only $1 a gallon, it isn't worth worrying about."

Larry
code5coupe

C4DC

Only distilled water here in Fl. With all the crap that is in the tap water, I wouldn't want it clogging the system up.