Joe, I do attribute some of my loss of mileage to the fuel we get today. Three years ago when we first got this bus it was not uncommon to see 8.3, but I have not been over 8 recently. I think Roger is seeing lower MPG numbers also, and he has also had good mileage in the past.
Because of the hills around Branson I could see my Pro Driver go down to 7.3, but since our return leaving the hilly area it crept back up but at the high end of miles traveled it takes a very high average MPG to pull up a low number.
I use that display rather than the calculated MPG because i have no way to pull the Webasto and the generator fuel consumption out of the numbers.
Jack, my assumption on the hitch rating is that the center of the ball has to be 6.5 inches or less from the bumper to have the 1500 # toungue weight rating. Any distance greater and the tongue weight is reduced proportional to the increase in distance.