When I first bought it, mine was at or around the 20's on the highway. I once posted a photo of the computer showing 20.8 MPG after a day trip.
Now? With a lift kit, 265/70 M/T's and roof rack catching the air? It's doing fantastic to get 14.5 on the highway, and 10 in town. BTW, the tire guys said those M/T's would "negativity impact the MPG." They weren't kidding.
On edit: I've reset the speedo with the Hyperchips programmer, so it matches the GPS. That means it REALLY DOES get as crappy of MPG as the computer shows.