I believe they were talking about using Sport mode on their F-150s.
To the others discussing fuel economy, it's been well-established that the Rebel with its lifted suspension and shorter (numerically higher) gearing will not get even close to the window sticker rating. In fact, you can pretty much deduct 1 mpg for 3.92 versus 3.21, and another 1mpg for heavier trim levels / more optioned trucks, versus no or low-option trucks.
Yes, these engines break in over time - currently my lie-o-meter says 16.3, and that's after almost 3,100 miles, mostly highway, almost all commuting, and a tiny bit of towing (60 miles).
-John