VernDiesel,
Towing the 8500+lb boat was quite a bit easier than towing the 30' Nomad Century TT because the boat's bow has/forms a much more aerodynamic wind cutter than the about 8' by 8' nearly flat TT front. The boat also has a less squared off rear which greatly reduces the strong constant vacuum sucking created by the air coming back together that the towed item had forced apart to go thru.
Note the shape of the higher speed airplanes and airliners fronts and rears! Easy efficient entry and easy efficient exit! Wind resistance progressively squares itself as speed (velocity) increases over approx. 44 mph and thus requires the multiplying of energy (HP) with its required fuel increases required to achieve.
A TT front on most is more like holding 2 4' X 8' sheets of plywood on edge vertically side by side being 8' X 8' in a 60 plus mph wind.
Poor aerodynamics sucks HP and fuel like mad. Rolling resistance however remains constant whether moving at 5 mph or 100 mph. Hint, I'm a retired 39 year mechanical engineer and an longtime engineering company business owner mostly working on automotive projects. in engineering, facts and only facts rule while opinions and BS is for fools...