Based on the search terms leading to this blog I see a few people are interested in our gas mileage.
Note that our truck is a 3.5L Ecoboost “Max Tow” King Ranch package. So the gearing is different (3.73) and its heavy.
Not towing we get around 13MPG.
While towing we average about 10MPG on the flat at reasonable speeds (70MPH).
This drops to about 8MPG at 75MPH (which is legal in many places where we drive, albeit ill-advised when towing).
On grades/severe headwinds/absurd speeds I have seen as low as 6MPG. We have tested all three conditions simultaneously – see next note.
Going up Wolf Pass in Colorado at 70MPH we must have averaged something around 0.1MPG. Maybe less – the MPG graph in the dashboard wouldn’t populate.
– Anthony, Waukee, Iowa