On Mon, 23 Sep 1996, Robert J Donahue/DELCO wrote:
> I heard several people warn against using distilled water at MG Indy 96,
> although they could not explain why. That sounds like an old wives tale
> to me. What could possibly be bad about using distilled water with
> antifreeze? Anybody else ever hear of this?
Yes, I've heard of it. It may stem from the fact that distilled water
sometimes has a pH substantially different from neutral. That shouldn't
matter, though, because the actual excess of Hydrogen ions needed to give
water a very acid pH is trivial. Another theory I have heard is that
distilled water may dissolve stuff, because it hasn't anything dissolved
in it already. I'm no chemist, but I would not worry about either of
these especially when the water is mixed with good antifreeze.
I've used nothing but distilled water and antifreeze in my cars for at
least 20 years. The radiators stay clean and I have no problems.
The problem with tap water is that the water contains minerals, which
precipitate out when the water gets hot. Obviously the problem is worse
in some areas of the country than in others, but these precipitates make
a nice insulating layer and plug fine passages. If you live in an area
where your Mr. Coffee plugs up periodically, or where the teapot gets a
layer of lime in the bottom, make sure you use distilled water in your
radiator. If you've used the same teapot for years, and the bottom is
still clean, then use tap water in the radiator if you want.
Ray Gibbons Dept. of Molecular Physiology & Biophysics
Univ. of Vermont College of Medicine, Burlington, VT
gibbons@northpole.med.uvm.edu (802) 656-8910
|