I get 16 mpg in my 1 Ton, empty or loaded, my commute is mostly around 25-35 MPH. I have stock (5.14) gears in the back end, and big bias ply tires. I like the low gears in the back, as I can shift into 4th at 20 mph.
In my opinion, if you are driving in the city, the only way you are going to increase the mileage you get, is to drive with a light foot. At the same RPM, you burn more gas with your foot to the floor, than with it closer to idle.
