My parents have a Durango with the 3.6/8 speed, it gets about 15 mpg average. My dad just putts around in it, but on the few occasions I've driven it, it scoots when I put my boot to it.
Also, the mileage goes up when I drive it like a normal person. My only real complaint is the auto shut-off/restart. Luckily there's a button to disable that "feature".
