I see the exact same argument on the BMW and Volvo forums. All of them swear by the ultra special dealer coolant because they have aluminum cyl head or aluminum block. Read the back label of your nearest Prestone bottle. You see the words 'aluminum safe' somewhere in there. And no, you don't drive your Mercedes more than the average honda or toyota driver. In fact I'm willing to bet there are a lot more 300k+ mile hondas on the road than Mercedes. But if it helps you sleep better at night knowing that you have Mercedes branded coolant in your engine more power to you. I'll be sure to let you know when my cheap green walmart coolant causes an engine failure.

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