Sorry it took me so long to reply... I don't look at these threads often enough. Actually, I try to keep it at the speed limit most of the time, but when I have gone 70 or so, it seems to do a little better on gas. But yesterday, my wife just took the truck to a town an hour away and back all on interstate at 75 mph and only averaged 13.4 mpg.
Getting pretty steady 13-14mpg now. Bigger tires, tool box and my 300lb bumper. Got 16 all highway running with an empty bed though, so it's still possible.
