I get about 16-17 usually on the hwy running 80-85 mph and don't really worry about it around town. I babied it up and down the road all last week running 65-72 mph and drove it like there was an egg shell between my foot and the pedal and got 21 mpg hand calculated. I was amazed to get over 700 miles outa the tank.
just hit 45k and the mpg are starting to slowly come up. for the first 30k i was getting 10-11 around town and 12-13 on the hwy. now i'm up to 13-13.5 around town and 14-15 on the hwy at 70-75. this is on my 07.5 with the 12'box/sail 4:10s the 6spd auto and a good load on it. i love this truck. its got to be the fasts bread truck around.