I've got a '97 1500 Ram with a 5.9L, 4x4, 3.55 gears and towing shift kit. I get about 14 mpg around town if I drive nice. Highway I can get about 17 if I keep the cruise on at 65.
Towing my 2400 lb trailer and my roughly 3500 lb Ranger it does pretty good, but only gets about 8-9 mpg out on the highway. I'm from PA and it'll pull that load through the mountains pretty good (I can hold 65, without beating it too much). All around it serves me very well.