The temp stamped on a stat is the "opening/closing" temp and has little to do with your engines operating temp. If you don't believe me, unplug your fans and leave your car running for a while. Your radiator regulates water temp not your thermostat. Your stats only job is to get your engine hot quickly by blocking coolant flow, then it stays open and does nothing.my4isrobs said:Depends what themostat you have in your car. There the same basic thermostat but be sure to look what temperature range it operates in if your buying a new one.. if it specifies an 84 degree c operating temperature and the one your replacing is an 80 degree c then your water temperature will change and the guage will read higher.
Hope that helps