Having nothing better to do on this balmy spring-like day in NE Tx, decided on a fairing efficiency project.
Using builders plastic, a coat hanger, and cable ties, I quickly slopped together a fairing of sorts for my TE.
Enlisting the assistance of my grandson, we set him to coasting down a 6% hill nearby.
Results: max speed with fairing, 25.5, without 24. Coast difference, 72 feet.
I'm guessing at least a 20% efficiency gain over my mess with one of those $400 custom jobs. Multiply that by 100 hills/1000 miles and maybe, just maybe, some tailwinds, plus the 1 mph flat ground/headwind gains. I'll let you do the math. Please.