Did my first long tour with the new F700GS. I carefully tried to fill each time to the same level. I calculated and compared my measured mpg with the computer's mpg and I came up with a difference of +/- 2mpg.

And sure enough, headwind and up/down on a road make the difference in mpg. I went from 42mpg going 70mph plus headwind on a 160 mile stretch to 60mpg cruising back country roads.