Where I live, we are said to have (objectively, by tests; and subjectively,
by taste) some of the best water in the state (California). However, it is
'hard' as it comes, it seems. You could leave a regular 12 oz. glass of
water out to evaporate and you won't be able to see through it when it's
done, especially towards the bottom. I service several swamp coolers every
year that I'll wind up getting some 30 pounds of mineral out of some of
them, including pads.
 You can just imagine what this stuff does to a coolant system when you
leave it in there. I've taken several radiators out of used cars I've bought
to a guy in town that reconditions them (for 75-100 bucks). You open them up
and you wonder why the engine hasn't blown to hell, especially in this
climate. After 24 hours in the bath, you can start to see into the water
passages. I usually get them back after four days, and they look like new in
and out, but he's pretty good at what he does.
Distilled water is .50 to .75 a gallon around here- you can get it cheaper,
I suppose, but why bother?
If you're talking about changing the coolant every two years, the water is
the cheapest part and probably gives the greatest return for the cost,
especially in a place like this. "Over kill" is what happens if you *don't*
use it, I think.

Cya,
Robert

----- Original Message -----
From: "Chuck Reisinger" <chuckphoto@EARTHLINK.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Saturday, February 12, 2005 10:32 AM
Subject: Coolant

A local VW repair shop told me that I don't need to use distilled water when
draining and changing the coolant (2 yr drain)....I've been changing my
coolant and brake fluid every two years...I'm comfortable with this
(recommended by the Bentley Manual)....

What are your thoughts about using distilled water...is this over kill....?

Thanks