I left Thurs afternoon to head to Lacy WA and google maps said about 1100 total miles there and back (came home last night). I had the cruise control at 3mph over the limit both ways and my Diablo in the 87oct performance tune.
This was through the main canyon and with a decent tail wind....slight uphill and speeding a tad headed back home
This was the same canyon going there with a head wind and lower speed ~68mph, this was at the gas station using my fuelly app
This was from Lacy, WA to Hermiston, OR and goes with the first pic
Overall my truck did great and I'm pretty impressed with my MPG's