I was driving on the motorway last week when it was really hot when i suddenly noticed that my temp gauge had dropped from half to just above a quarter, in all the time i've had the car it's never moved from its normal running temp (middle) is this a common sign of imminent failure?

Also at the same time my fuel gauge increased by quarter of a tank and the range comp increased too, have i got an electrical issue or more mechanical?

Its also started to take longer to start too.

Any ideas?