my car was running a little hot for my liking touching the 100 mark on red lights etc. but dropping after a while when I get moving. The aux fans work, the fan clutch works and was engaged when the temp was near 100.

temps on the highway are controlled at 90 - i.e. between 80 and 100 mark. Sifting through the stuff I got with the car, I found a genuine MB 85 degree thermostat with 606 part no., a wahler 80 degree stat with the bypass valve made like a flat disc unlike the MB thermostat which have openings in it.

and a new looking BEHR 85 degree stat which looks like the MB unit (but this one was bad - it did not open even when left boiling for 5 minutes)

Called the miserable stealer - and the stat they have for the 606 be it 124 body or 210 body is 85 degrees. ?? Im puzzled that how come the 210 body 606 engines run at 80 degrees with an 85 stat. And running an 85 stat causes the engine to run at 90 or 95 which is nearly fan engaging temperature.

So kindly clear this up for me. Does the 606 come with different temperature thermostats?