I regularly get 380 - 400 miles to the tank, just above the red mark, out of my 120 with normal driving. If I drive like a real Granny I've seen 450 and that is trips involving M3, A34, M40, and no more than 65MPH to achieve that.
A scangauge 2 is a good thing to have if you want to stop flooring the throttle. I switch the MPG off during track days when I regularly see 9 - 11 MPG.
