Well, very good questions, Mike!
But you already use the Mercedes Antifreeze/Coolant, so let's not be comparing Japanese autos to Mercedes, shall we?
Seriously, no one to my knowledge has said that "...non-MB coolant will destroy "plastic" parts in the MB vehicle...
. Strictly hearsay at this point, but I (and other members) have heard from several sources that the phosphates do contribute to making the plastic coolant tanks brittle before their time.
And the "soft" plastic used in bottles in no way compares to the "Hard" plastic in radiator tanks. Two completely different types of plastic. For instance, the "soft" stuff wouldn't be able to take the heat and pressure of the radiator and cooling system. :p
Now, as for aluminum. There are various formulas for making any alloy, and the Japanese, American, and German auto industries all use different formulas. So they are really not "pretty much the same". Besides, aluminum is only one engine component that is part of the overall "problem" with using an Antifreeze/Coolant with Phosphate corrosion inhibitors in it.
Hey Mike, maybe you have really soft water where you live, and you have just done an outstanding job on maintenance?
Or maybe they'll both fall apart tommorrow...
So why is it that Japanese auto companies call for a "low silicate" Antifreeze/Coolant, while the German ones prefer "high Silicate"? I don't know as yet, because so far, it hasn't mattered to me as someone who doesn't own any Japanese cars. But I'd venture a guess that they are two entirely different engine systems requiring substantially different forms of maintenance? Just never combine the High & Low silicate formulas, or they will form a gooey clog.
Finally, when is all said and done, just why are the Japanese auto companies themselves also reformulating Antifreeze/Coolant specifications on their cars to be similar to the organic acid corrosion inhibitors that everyone else is making to copy Mercedes?
[Edited by longston on 02-28-2001 at 02:35 PM]