Post recording edit: I drove from Loveland to Denver and saw some pretty impressive fuel economy numbers at 75 to 80 mph. well I did this test at 70 I might need to redo it at interstate speeds. now back to the original commentary below...
I have wanted to do as pure of a highway test as I could, in the most ideal conditions possible. I did some research and found Highway 14 between Ault, CO and the turn to Keota, CO only gained and dropped a max (at one time) elevation of 200 feet. Now the total net gain/loss was 1000 feet over the whole trip, but by our standards here, that is FLAT!
I only had to pass 1 vehicle each direction during this test, so it's as accurate as I could make it for the almost 80 mile highway speed test.
I tried to mimic The Fast Lane Truck on their MPG testing, filling up until the click, waiting 30 seconds, and then "topping off" one more click.
Ironically the drive back to my house from Ault ended up netting me over 16 MPG, that will drop rapidly as I drive around town now.
Coming up in January I have a weekend job to install in Custer, SD and that 5 hour road trip will be a great highway test as well with varying terrain. Will probably put those results on instagram.