Phil, I installed one of those Scangauge things on my truck, and I get terrible mileage at very low speeds. When I am not towing, I can get (at best) 24 mpg at 58 mph. When I am towing, I can get 13.5 mpg at 52 mph, at best. Add wind or a hill and things get a lot worse.
So when I am crawling along a rough dirt road with my trailer, I have a solution to the mpg issue -- I do not look at the gauge. (I am too busy steering around the rocks and the holes, anyway.)
Think of it this way -- the rougher the road, the more likely you are to find perfect solitude! Most people do not want to scratch up their vehicles or risk having to dig themselves out of the mud or the sand.
