I have a 2013 5.0. This weekend I had to tow a trailer to southern Illinois to pick up a motorcycle. All the way, I was getting 13.0 - 13.5 MPG towing the small trailer. As luck would have it, the trailer wouldn't fit my new trike. I had to rent a (much larger) trailer and with the trike loaded, I got 10.0 to 10.8 MPG. On the return trip to bring the larger trailer back, I got 8.0 - 8.7 MPG. The return load was with Shell gas so I am guessing that their gas didn't have the combustion potential that the other gas (Citgo) did. After swapping the trailers and heading back home to Indy, I got 13.7 -14.0 MPG.

Gas issues aside, I was very impressed with my truck. The one issue I learned was that for very heavy towing loads, you need to decrease the speed to allow for the truck's engine size and ability to tow heavy loads in 6th gear. Once I dropped down to 60 MPH, the truck always went to 6th gear on flat grades. Any faster and it stayed in 5th which is why my mileage suffered.

I don't plan on towing anything in the near future, but I am impressed with my truck for handling something it was born to do!

 

I pull way more then people think this 5.0 can handle. I would put them to any 3.5eb any day of the week. But with my 18' car hauler and rzr xp900 I get around 15mpg at 80mph. You choose the right truck for towing. Heck im buying a 30' 5th wheel toy hauler to pull behind mine.

 

How fast were you going? What is the rear end gearing? Heavy or light traffic? And it is winter gas now, so expect mpg to go down 1-2 mpg. The nice thing is that gas isn't that expensive right now.