The thermostat is a 195* thermostat, so it is supposed to be somewhere near that. Mine ran at 210 for a couple of years until it would overheat after a few hours on the interstate. Not by much, just a few degrees, but it sent coolant everywhere. Once I replaced the thermostat (wouldn't surprise me if it was the original) and the radiator cap everything was kosher. Now I run at or just barely over 195* all of the time.
So, not really an issue I guess, but I have no idea what would cause that. The heat in the cab being different is probably just in your head. Have you tried reading the engine temp from the OBD port to see what the temp really is?