2017 Thor motor coach 23tk on ford transit 350hd chassis with 3.2 diesel powerstroke, I get 16mpg all the time. I’m the original owner, jus put new tires with ford original rims. Add 375 watts solar painel,2000watts inverter, 2  lithium battery’s , front bumper guard with extra lights,webasto diesel heater, shower door and much more.if you have any question or like to see more photos videos. Please call Luis at 857-991-0447. Thanks