We get 10 to 12 MPG depending on terrain, wind, and how big of a hurry we are in. Traveling approx. 60 to 65 MPH on flat interstate with no headwind we get around 12 MPG. in our E-450 2012 Triple E Regency GT24MB (almost 25 ft.). We travel fully loaded with food, clothes, two people and one Basset Hound(plus extra stuff), with water tank 3/4 full and grey and black tanks almost empty.