Mine averaged around 50 mpg, but there's a price to pay for that
It was one of BMW's first euro 4 motors and it runs very lean..... A real pain in the arse at low revs. A power commander transforms the bike but fitting it is a nightmare
You will love it. Blow off almost anything at the lights
I get 45mpg out of my K1200R from my 40 mile commute to work which includes some 'brisk' A roads and 10 miles of London traffic.
MPG does drop if you sustain over 90 for any length of time though