I got an early 2011 that has a 20% program, no particlate filter, no cattlicatic converter, no DEF but still hav erg. That picked up about .5 mpg. Pulling GN, around 9. Farm work, bumper trailer, etc, around 13. No load on highway, 15 and 15+ with tailwind, down hill. Doors raddle, wind noise, SMALL fuel tank, 20" tires, needed air bags, and other things. The thing that POs me is when you stop, get out of drivers door and want to get in the back or passenger door, the damned door is LOCKED!
It is pretty when you can keep it clean. Red King Ranch crew SWD. I like Cummins but not Dodge trucks and definately no GM products. That is why I drive my 2010 Sienna van most of the time.