| All the Mercedes coolant I've ever used has been the amber colored stuff. I'd still not mix the two. There is a maintenance interval specified for coolant changes and it is every three years for my car. A flush is not needed if your old coolant comes out nice and clean. Measure how much you get out and compare it to the capacity. When I did mine, I got all but a quart or two, so I refilled it with water a few times a drained it again until it was clear. This time since I know what I did the last time, I'll just drain out the old, maybe rinse it once and then refill. When I refer to "flush," I mean a deoil/descale process - not necessary most of the time.
Len |