Helix hit the nail right on the head, put a real gauge in there and see what the temperatuare actually is. Mine was running about 1 needle width above halfway, which I thought was fine, until i put my autometer in and found out that equated to 220 degrees. Ive since done the electric fan mod, and a fluidyne is on its way. Im not sure on this one either, but having a stuck open thermostat would only slow down how fast your car got up to operating temp, it would not make it run cool all the time. Also, have you done any mods to the cluster, white face gauges, ect. Is there any chance you or a previous owner put the needle back on in a different position. I would definately explore it further, because what happens one day when you have a true overheat condition and your gauge does not warn you in time.?