My 2001 V-10 F250 4x4 gets 9-10 mph in town; 15 mph on the highway; and about 9 mph when towing a 10,000-lb 5th wheel. It does really well towing - there's no hill we haven't been able go up - but it's occasionally 3rd gear, 42 mph and 4K rpm through mountain passes.
I'm selling this truck right now, if you're interested - look at my add in the web site classifieds.
~~~~~TrekChick