I have about 3k miles on my '16 TEP, and I was curious how the highway mileage was.
I did two tests. Top tier gas used.
~121 miles, flat, CC at 71mph, AC on - 24.7mpg calculated. I-90 in Ohio.
~135 miles, rolling hills, CC at 74mph, some AC - 23.6mpg calculated. (It had to drop a gear a couple times for a few seconds on a couple slopes.) I-77 in Ohio. Also, there was a stretch of about 6 miles where the speed dropped to about 60mph in construction, and I used CC for that part as well.
Again, this is not going by the trip computer-- it's calculated from amount needed to refill the tank. Now, there is always the small differences in gas pumps/topping off etc., but I tried to keep it as even as possible by topping off with one squeeze of the pump handle after it stopped.
Very pleasantly surprised by this. But any sort of mixed driving brings it down to 19-20mpg.
Just thought I'd share.