I have about 300 miles on a 330i.
The lifetime economy so far is 21.7mpg.
That's almost exclusively short trips in the city, in stop and go traffic. I've not had a chance to drive highway for more than a couple miles at a time. So far that is just slightly better than my old 2016 GTI DSG.
I'm trying to keep it below 4k rpm most of the time at least until I hit about 1000 miles, but I definitely get into the throttle at every start
.
I am guessing that pure highway driving will net mid 30's.