The bottom radiator is now warm with the new thermostat. With the old thermostat, it was cold (same 12 miles local commute route). The old thermostat is also rated at 80 degree C.
The outside temperature at Bay area now is around 45-65 degree F. With heater on and no AC, running near 100 degree C is too hot.
Some reference from Mercedes maling list:
http://db.mercedes.cx/mb/200204/03/0006.html[/URL]