Mine behave's the same as PJ's.
I rarely use the aircon or heater because both are useless. So with all of that turned off, it runs cool in hot weather (95 ish) and hot in cold weather (100 ish).
It also reads half full when full of fuel - and the dial wanders around like a drunk.
I've learned to ignore these things.
I wouldn't ignore one of my wheels going past though!
