Truck Camper Mileage (Question Answered)

I get 11.9-12.2 MPG with my camper on and 20+ MPG running empty. I very seldom run empty. My overall MPG for 63,378 miles (last fill up) is 11.95 MPG. I live full time in my unit. I pull an 18 foot long, 8.5 foot wide, 10 foot tall enclosed tandem axle car hauler and usually don't drive over 60 MPH. Going 65 MPH on a 2200 mile trip with my truck camper and trailer dropped my mileage to 9.1 MPG. (I needed to be somewhere with a very short notice.)

LeRoy

Edit,I added at 6:06 PM on Dec 12, 2018:
The total amount of diesel from my log book: 5316.951 gallons.