I am a guy who keeps track of every gallon of gas that goes into the tank. My first MH was a Dodge 360 in a '76 Fireball of 21' that gave 5 mpg on a good day. Second was a 27' Jamboree '89 with a 460 Ford that 6.5 overall. Next was a 35' '96 Pace Arrow with 454 Vortec that gave 7.25 mpg. Last big one was a 2003 Mountain Aire 38'with the 8.1 Chev. and that gave 8.5 over the 11 years I owned it. I bought the Roadtrek last year and have put 6K miles so far with 17.3 mpg. The 1975 GMC is in the shop now after first use and 4 mpg. I just took it as a trial knowing it needed work. As the engines got newer the mileage increased.