Most of the time I turn on the AC when the gage reaches 200 or more if I'm stuck in traffic. With the AC on, it stays around 195 or so no matter if the car is on the freeway or idling in traffic.
Without the AC off, however, it regularly reaches 220 in traffic (but never at highway speed) and the fan turns on to bring it down to 200.
Both my '92 and '93 have done this since I've owned them, and my '93 has a recently installed 180 tstat. My 2 bonnies are both are supercharged, and from what I can tell, the supercharged engines run hotter than the normally aspirated engines.
'99 Bonneville SLE, white, 112,000 miles
'02 Park Avenue Ultra, white diamond pearl, 88,000 miles