A thermostat rating of 160.....or 180, 195, whatever, is the temperature at which it opens and allows coolant to circulate. It is NOT the temp of the the coolant itself. Typically, the coolant in a warmed up engine will be higher than the thermo rating.
That is EXACTLY why I appreciate this site, my other 96 imp has a stock 180 and it is programmed so it stays pretty much dead on the middle.. This 96 I believe has a 160 stat with no programming, and it runs pretty steady at 1/4 on the dial pretty much all the time. Except sitting at a light with ac running it curls up to half.. cwm3cwm6