We just went on a trip to Yellowstone and drove 3,554 miles. I got 43.2 mpg ... and would have been better if not for Montana, with its mountainous roads. I was in EcoMode the entire time (except, obviously, when it needed Power for some of those steep hills). I should note I also had the a/c on most of the time. I rarely use it, but with 4 of us in the car, my wife and kids were complaining about being comfortable or something like that.
Was that you I met at the Old Faithful Inn with the Silver V? 43.2 is not bad. See my post under 1966 mi trip. I probably drove a little slower than you did .
I drove my 2012 hatch back 7112 miles in June. I drove the west coast, 6 national parks including Glacier and Yellowstone. I used A/C most of the way, used ECO the whole trip and averaged 50.8 MPG.