So are you saying that Mercedes offers a mixed and unmixed antifreeze?

MB doesn't offer a premix. If they did I'd buy it.

First of all some definitions.
The term purified water refers to water which has been produced by distillation, deionization or reverse osmosis. Simply stated any of the three methods can produce water of the same chemical purity for practical purposes.

I would say that if the choice was given to make a few gallpns of a 50 percent solution of antifreeze the 80 cents or so that a gallon of purified water would cost would be immaterial.

Finally you would not be adding iron, chlorine or any other substances in tap water to your brand new antifreeze solution.

Purified water has a known purity, tap water is all over the place depending on the location and even he time of the year. In the northeast, after the snow melts, lots of salt runs into the rivers that provide our water.

That's why I make my coffee with purified water or spring water, it just tastes better and is crystal clear.

Distilled Water is the Winner for me.

Thank you everyone for participating in this thread and for all the educational information you provided. I really appreciate it. I used to use tap water as a mix, not knowing any better...never again.

The 2 conflicting arguments I have heard go like this:

Distilled is good:

Contains no chlorine
Contains no minerals which can deposit or errode components
Is neutral pH

Distilled is bad:

It's hungry for ions, and it's going to get them from your cooling system components.

This "argument" is only valid if you run PURE DISTILLED WATER! (See my first post in this thread.)

When you mix distilled water with antifreeze you no longer have distilled water, but a solution of ethylene glycol and water with a bunch of chemicals from the antifreeze product that perform the corrosion inhibitor function, and you have not added any undesireable chemicals such as calcium and chlorine.

Get it?!

Duke

So...
 

What about deionized water?

Deionized water is for all practical purposes the same as distilled water.
Deionized water is NOT the same as softened water however.

Job 20-010 of the MB M104 Engine Service Manual states:

"Use water which is clean and not too hard. Drinking water fequently, but not always, satisifes requirements. The content of dissovled substances in the water may lead to corrosion. If in doubt, use distilled water."

Is the above still MB's official word, or has it been superceeded?

Also, "de-ionized" water is "hungry" for something, so I wouldn't use it, when distilled water is cheap and plentiful.

Thanks in advance,
:-) neil
1988 360TE AMG
1993 500E

BTW- here's a link of the actual text, scroll down to bottom, and read the last sentence:

http://www.silcom.com/~neilv/sportli...lled-water.jpg

In 30 years of owning and driving all sorts of cars...I have always used tap water or well water (where i grew up) with no problems. I can never remember having a radiator problem...

Of course, I change the coolant every two years. I use zerex g-5 for the Benz's

Lee, I guess you don't own your cars long enough. On nearly every car I've maintained according to manufacturer recommended schedule, the radiators have, on average, needed replacement after 10 years. Tap water.... distilled... it made no difference.

I've seen failures where good intentioned ppl used distilled water....

my 72 280se was 26 years old when I sold it in 1998. I owned it for 12 years , I can't recall if the radiator was original or not. This car had 153k miles when I sold it.

my 1990 q45 had 167k miles when I parted it out this year after owning it for
12 years, I took the radiator out and gave it to a friend in Columbia, SC

Guess I have been lucky.

The only new car I have ever owned is a 1998 Ford Expedition. That is 7 years old with 136k on it. Original radiator.

I don't know if my current e or ce has the original radiator or not...guess I can check tonight.

I use stale beer and coolant. Equal portions of each.

Does IPA or Stout work better?