I have a 2012 crew cab 5.7 4WD with a little over 102,000 miles on the odometer. I pull a 12-foot double axle trailer with it fairly regularly, usually fairly heavily loaded. I also use it off-road quite a bit, but most of the miles are highway miles, as we live a long way from just about everywhere and everything, except scenery. So far, the truck has been trouble-free--nothing but the regularly scheduled maintenance.
Mileage has averaged a little under 18 mpg for the several thousand mile intervals for which I have kept records. I have seen over 21 mpg running with a good tailwind on the interstate and I have seen 14 mpg heading back into the same wind. I mostly drive the speed limits these days (except on rural two-lanes with posted 55 mph speed limits). If I stay off the interstates, I almost always average between 18 and 19 mpg on long trips.
It's a comfortable, well-made truck, and I wouldn't hesitate to buy another one.
