Hi - does anyone have a sense for how much worse their mileage is with a given tow vehicle on a 19 vs 17? I currently have a 17ft Casita and would like to upgrade to an Escape. My tow vehicle is an F150 (V6 EcoBoost TT 3.5L), I get about 13mpg pulling the Casita and I'm guessing that I would get about the same with the Escape 17. I would like the roominess of a 19 but I have no idea how the extra weight, height, width and road friction from 2 more tires (2 axles vs 1) might affect mileage.
Any thoughts or experiences would be much appreciated!