I have the 20” winter tyres now, definitely a lot less noise and like the way they grip (for winter tyres).
I will for sure try 21” summer ones next spring.
Interesting stuff. I'm driving an E-Tron GT (so close to the 4S I believe) and created a log for two recent trips through Germany. Happy to share the data, as it perhaps is insightful:
These were two trips with, at the first 400km, a lot of traffic or bad weather, driving on winter tires...