I own both a Mercedes (86) and a 1999 Chevy Crew Cab Dualie,at 18 and working in a parts store, I have cheap access to Various products and use them/abuse them at little cost to myself. (1.5k Mile Mobil 1 oil changes, 10k mile Brake Fluid changes, I have too much time on my hands even though I am full time enrolled in College aswell). My Truck came with the red DEX-COOl Antifreeze and I have been VERY UNSATISFIED with its performance. There isn't one fitting on the coolant system (quick release fittings)that I haven't had to replace, the "Dealer Only" Intake manifold gaskets(Have water passages in the intake manifold) which also went down for the count because of corrosion. Dexcool is much much more corrosive than the regular green stuff. Chevy water pumps tend to go right at about 50k miles, I know as my dad has owned 13 chevy trucks in the past 15 years(No, Not because they were junk). Now with DexCool at 7.99 per gallon vs. 4.79 per gallon for Ethylne Glycol Green Antifreeze, we see why manufacturers are pushing for usage of DEX-Cool.

As for the Mercedes aspect: When I bought the car I flushed the radiator within 3 days. I refilled with a proper mixture of 50/50 Green and (gasp) Tap water. I change it every 30k Miles and have absolutely no scale, grease build up, or corrosion in my motor (I've pulled the head) or any of the exposed coolant pipes. As far as water pump life goes, Water Pump bearings are sealed, the minute that the seal fails and exposes the bearings to engine coolant (coolant leaks from the weep-hole) the Water pump is supposed to be earmarked for replacement. So special antifreeze doesnt make much of a difference.

Distilled Water: Distilled water is added with the intent of keeping minerals out of the coolant system. Did anyone ever consider that an iron engine block that is constantly in contact with the coolant might shed a few minerals here or there? Remember that most mercedes are iron blocks with aluminum heads, so the effect on the coolant is still similar to that of a (dare I say it?) Chevy or Ford....

Keep on your wild goose chases and quotations of great authors, I'll just change my antifreeze once a year. Besides, 150k mile change interval? Now who sounds ridiculous?


Jason M.
1986 300E 88k
1999 Crew Cab Chevy Dualie 7.4L 90k
ASE Parts Specialist
Student at UCF