My plus 8 is the same it has two operating temps - about 90 and about 100 depending on conditions. Speaking now with a bit of BMW knowledge there are two things to consider.
Firstly Bmw normal on a BMW temp gauge spans quite a range of temps which hides what I think is intended variance between low and high operating temp at any point in time whereas on the plus 8 it is the actual temp that is shown due to the set up of the gauge.
Secondly on a bmw straight six the thermostat housing has a mechanism to change the operating characteristics of the thermostat from the ecu in that it has a heater element controlled by the ecu. I suspect that the V8 has a similar mechanism and the running temp is dependant on outside temp plus other variables.
