I have been averaging 54 mpg. I now have 3500 miles on my F800GS. I love this bike.
I live @ 5,000 ft. and today did a ride to 11,000 ft and back. It covered 143.7 miles according to my gps from fill up to fill up. (1/2 mile from my house). The bike took 2.116 gallons of gas for 69mpg. Yes I rode easier than usual but didn't baby it. Those are Vespa #.