Hi,
My sister traded in her nearly new 1500 GM truck for a F-150 Ecoboost. She is really impressed with the power too! They used to have a 5.4L Expedition as well. Make sure that you are using 91-92 octane gas while towing, or it might tend to ping, and the controls will change the timing and inject more fuel to prevent pinging, thus less MPG while towing on lower octane fuel.
I notice that my MPG also is less on lower octane fuel in my Kia with direct fuel injection. I get 33 mpg with 92 octane, and only about 28-29 with 87 octane.
Have fun!
Fred.
