Driving to work the last few days, I've noticed a peculiar phenomenon. My route takes me on a motorway for about 10mins then what is essentially an A road for 40 mins. The car warms up whilst driving down the thankfully ice-free the motorway, but as soon as I start on the smaller roads and driving slower with lower revs, the car cools down again to the 50 degree mark. Is that normal? Its -22 here and I have the 140 TDI. On another note, the last couple of days when I've been driving, its felt like the brakes were on slightly. I've checked that it wasnt snow or ice building up in the arches so wondered if it maybe the brakes were frozen on somehow, if thats possible?