In the Touring an Travel forum I have an older post about a trip I took in May. I rode from Ohio to Tennessee to North Carolina and back. Below is an small portion from that post regarding my fuel use.
Total riding: 1847 miles. (482 miles during 3 days of camping, the rest traveling). Highest Altitude 5970 feet above sea level (day 04). 2008 Gen II FZ1 with stock seat, stock windscreen, SW Motech bar-back risers, Satan highway pegs, Mivv GP pipe, AIS blocked, header cat intact. Rider 172 lbs, excluding boots, hard armored riding jacket and helmet. Total Other Load 61lbs (17lbs hard case & 44 lbs camping gear, clothes, full rain gear, etc).
Longest distance between fill ups 163 miles, average MPG 44.57, average fuel price 2.73 per gallon, average fill up cost $7.61, total fuel used 41.73 gallons, total fuel cost $114.16. I ran a GPS tracking app on my Droid phone during the entire trip, it tracked my speed, altitude and heading in 5 to 6 second intervals almost the entire trip except for a few times I couldn’t get a satellite signal (such as the West Virginia mountains coming home).
Most of the highway riding was at about 70MPH turning around 4000RPM on stock sprockets. I was pretty happy with the overall MPG. Had I been riding with sport bikes rather than cruisers I suspect my MPG in the mountains of North Carolina would have been in the low to mid 30s.