I really didn't want a disscussion on the aerodymanics of TTs.
Most TTs are not shaped anything like a wing, so I am not sure what the thinking is there.
But if aerodynamics must be considered, I want to make this observation.
Most TVs nowdays have spoilers or air dams to keep the air passing under them to a minimum. Most TTs will have a lot more ground clearance th than the TV towing them. I would think that this would create a low pressure area under the TT that would ten to increase downforce,,, But it probably doesn't because the sides of the TT allow air to get in, filling the low pressure area. At any rate, I do not buy the wing theory. And the underside of a TT is often pretty dirty as far as airflow.
Of course if the lifting of the TT is right, then that means that the 1/2 fans can tow even more! :B
I haven't tried this yet, But if I were to take a rectangular box, and hold it out the window on the highway in different positions, then that would be a pretty good test of my thoughts. I think I know what will happen