Eleven years ago I had a 22' 5,600# TT that I pulled with my F-150 SCAB with the 5.4LV-8.
I found a wind deflector from a firm out of Canada and for less than $300 I took a shot.
It was easy enough to install and or remove when not towing and I used it for 3+years with very good results. I don't remember what gas costs back then but it consistently got me an additional 1.5 mpg and paid for itself in 6 months. I based the fuel savings on repeated trips to locations I had visited before, my Scan Gauge and at the pump computations as well.
Without the deflector the front of my trailer was a always covered in bugs but when towing with it the front o fthe trailer was always clear and clean as the air flow was clearly being deflected up and over the front of the trailer.
A mother factor that contributed to its efficiency was having it mounted so far back, at the rear of the shell. I doubt it would work as well if i thad been mounted on the cab of truck with no shell.
Lots of skeptic's out there but I know it worked for me.
:C
