I'm happy to see the mpg numbers too. We towed a 17' Caravel
for thousands of miles and got very close to the same mileage. We now have a 26' Overlander and saw the same type of mileage, although it is gutted right now. It seems like the mileage is dependent more on the size and shape of the trailer than the weight -- on flat ground anyway. I'll be curious to see how it changes with added weight.
Thanks for posting the CanAm pic of the hitch reinforcement. With the larger trailer, we'll have to do something like that ourselves.
BTW, ours is a 2007 CDI. Unfortunately, we are on our second transmission. We have been given advice to keep transmission temperatures low while towing and manually downshift while climbing hills to reduce torque on the tranny.