That's really interesting. Do you notice a difference while towing? Why didn't you go farther up on the nose of the trailer?
It really does make a difference, I had towed my trailer for the time last year and was not impressed by the amount of wind drag it caused, I thought it would have been a lot easier to tow than my 8x16 flat nose enclosed tandem axle trailer, the camper trailer is 7x14 1/2 and has almost the same weight. My first trip was almost 3,000km and only averaged 17 mpg.
This year I first tried to add a heavy rubber mud flap across the rear bumper of my truck and a rubber mud flap across the front bottom part of the trailer, I wanted to slow the wind going under the truck and trailer, I was so proud of the job I did, it looked really good and had worked on it a good part of the day. I test tried it on the highway and it made no difference, I could still feel a lot of resistance with the wind and the rubber flap on the trailer had started to rip on its first test run. I then added a redneck prototype made of a tarp, angle iron, 2x4s and bungee cords, the tarp went from the top of the tonneau cover to the trailer, it was really windy that day when I test tried it, I was so impressed with the difference it made going against the headwind. My truck had suddenly shifted down two gears to 6th during the test run going against the wind, I looked a the rear view camera and noticed that the tarp had fallen off the truck and was laying on the front of the trailer. I stopped and reinstalled the makeshift tarp and continued on the highway with the truck going to 8th gear without struggling. My wife said she would not go with me if it would look like the way it appeared so I made a better looking setup using 1” square aluminium tubing for the frame and even rolled it to the same curve of the front of the trailer. I used the mesh of a 10 foot trampoline, I would have gone higher up to the window if the trampoline had been 12 feet.
I achieved 20 mpg or 14L/100km hand calculated for this last 10,600km trip, it does not sound that good but it is really windy in Newfoundland and the highway has very steep grades, I was surprised to see snow on the mountains in July. My truck was mostly in 8th gear except when near the mountain highways.
I was questioned a lot during my trip about my airstream setup.