gotta love the 36 gallon tank in my 13 F150 especially when you're towing. Drug 7000 pounds from Amarillo back to Houston getting 12.5-13mpg at 75-80. Granted not through mountains, but a lot of up and down coming through the hill country.
The 36 gallon gas tank and the Ford interior are why I have a Ford and not the Toyota. I looked really hard at both. My wife wants a Seqouia, but we're waiting for the 2014 Expeditions with Ecoboost.
That being said I don't think you can go wrong with either, we sometimes wish we had a little extra space in the truck when we have the dogs with us.