Well i went and did my MPG test run and came out MUCH better than I thought I would.
I did a round trip from Mid town kroger fuel stop in ashland to grayson and back.
I did not try to drive fro max MPG i ran 65-68on flat ground and held to floor on the hills. It only dropped 4 MPH on any of the hills.
I made sure to use the same pump and fill to same point (lower lip of filler pipe)
Result was 49.4 miles and 4.2 gallons of fuel used for 11.7 MPG.
I had heard these 12V cummins got good milage, but I didn't know it was this good.