 Now that I own the 5.4 liter, FLEX FUEL VEHICLE, F-150 4x4, I am realizing a very poor "gasoline" fuel economy of about 10 MPG highway which is much less than the 18 MPG that was posted on the window sticker.  E85 is much worse.  The non-adjustable seat bottom revealed itself as a rear end problem after the first 200 miles.  I am not sure what the engineers at Ford were  thinking when an adjustable seat bottom was not added to the lower lines of pickups.  I would have been happy with even a manual adjustment.  I don't think that these problems are going to disappear as my wallet gets much thinner.