No, it's not that technical on the MQB VWs. It gets hotter with RPM is really all it is - steady 2.5-3K highway driving will send it up, slower around town driving where you are at lower RPM will let it drop. The gauge is off a sensor so the values are real, not an estimate as someone above suggested.
Originally Posted by BrandonT
A lot of these modern cars have variable cooling. I know my BMW M235 did. On the highway it run 235 degrees, but when I put it in Sport and hit the track it would actually drop to 225. So it would run a higher temp under low load for fuel economy, but drop down when really under load. Maybe VW does this too?