[Peter_R]

This all depends on the vehicle manufacturer. Some sensors are in the engine block, so you see the actual engine temperature. Others and this may well be for BMW have the sensor closer to the radiator or should I say after the thermostat.

I am only guessing here, but it sounds as though yours/mine is after the thermostat and as it only opens partly and slowly and hence gives you a very low and slow reading.

In the UK mine indicates very quickly and goes to the midway mark of just below 100 degrees Centigrade (212 degrees F). There again I am in southern England, and generally it does not get very cold and so responds relatively quickly compared to the OPs.