I used to get +2mpg with my 96 6.5TD towing my Bobcat trailer at 18K GCW vs my TT at 14-15K lbs gcw. All because of the additional 20 sq ft more frontal area. ALong with typically on a grade, I could be a bit faster, and a gear taller!
The max sq ft the current tow ratings is 80 sq ft. How many normal full height RV trailers have less than 80 sq ft of frontal area? So with that in mind, How many of you are over your tow ratings with your almighty ICE rigs? Thought so! QUite a few of you! as was I at 90 or so sq ft. Not to mention in that 96, I was over my gcwr per GM of 12500 due to the emanual tranny vs the POS 4L80E at 14500 gcwr!
Weight as mentioned is not a killer for mileage, wind resistance is MORE important than weight!
Just like generally speaking, a 5W with no bedroom slide, smooth fiberglass sidewalls will net the best MG at any given GCW vs other styles of trailers. AN airstream is close! Not quite. A tenth or two less mpg.
Marty