My 85 Euro wagon normally runs with an engine temp below 60. Hard driving it I t gets to 60 and really hard driving up the mountain doing 70 on a 100d day gets it to almost 80... Whereas every other w123 ran at 80 or higher normally. It's low enough in this car that I suspect the gauge being off. Could this be due to a lower temp thermostat in the car or? I ask cause I've always seen 80-85 being the optimal temp.