I hate to say this about my friend Scott L., but me thinks he has been at the winery too long. If he, or any one else, would just take time to read the label on the Prestone antifreeze container, you might find some facts that might surprise you. You may find that it is as good as the stuff made by Valvoline for Mercedes. It(Prestone) may be even better,since I have never had to replace any of my radiators that had Prestone. I did have to replace the radiator in my 1983 300SD last summer and it had the Mercedes antifreeze.
As for the number of companies making ethylene glycol, I was told by a knowledgeable person that there were only two companies in the United States that made ethylene glycol. Maybe he too had been at the winery too long.
Bill Lewallen:Lexington,Ky. Home of Valvoline Oil