I once had an RV salesperson tell me that my Durango SUV can pull a 5th wheel. The WOMAN was very persistent on it too. In her world, you could install a hitch on the roof (and reinforce it) of a Prius. However, you'll probably get worse mileage and that's not taking it on the highway hauling a few tons. 6L/100km is worst case winter driving conditions. Most folks that I know who own one get in the 4.5 to 5L/100km range. Mind you, they drive it frugal. My 5.9L V8 dodge eats more than 21L/100km. I get 23.4L/100km, roughly 10mpg, towing 2.5 tons or roughly it's own weight in 100% city driving.