I got 71mpg (measured) out of my first full tank of fuel while running mine in.. I averaged 63mpg over my entire 1,900 miles on it so far, as indicated by my fuelly sig..v
I'm a sixth gear rider, I don't go much above 6000rpm in any gear, I short shift and plan well ahead.. I've taken advanced tuition in the past and adapt the 'system' to my riding.. I'll pull my fuelly stats up and edit this post..
This is with a standard screen and mirrors, no panniers, a 46L topbox, I weigh 15 stone, I don't hang about..
I can get 55mpg from my zx6 when touring on fast A roads, 70-80mph..
To get 54mpg from the Glee I'd have to be using more of the revs more of the time, and hooning around, and that's not why I bought the bike..