I have a TCH that I drive in the North (RI) in the Summer and South Florida in the Winter. In the Summer I have averaged between 42 and 45 mile per gallon per tank. In Florida in the winter I average only about 37 to 39 mpg per tank. I think a lot of the variation is just caused by the environment that we drive in. In RI I live in sort of country area so I drive much slower (two lane country roads etc.) and in Fla I am driving much faster due to higher local speed limits and sometimes longer trips (Ft Myers to Miami etc.)