Got back from a round trip to the Great Smokey Mountains aka Cherokee NC. round trip was abut 296 miles, pulling my pop up trailer and all the gear about 3k lbs. I have the 4.7 with the 3.55 and was surprised that I got 14.8 mpg. hand calculated. this included the 45 min backup at less the
15mph that I sat in on I40 west. Also I listened to the GPS bad idea
and was on some road with 9% grade up for 5 to 8 miles at a time. for that I used tow haul and the truck had no problem at all. I dont know how can I say this any better I LOVE MY TRUCK !!!!!!