I don't keep up much on newer Fords but does your F150 have a V8, V6.
is it dual exhaust into single or dual exhaust all the way back with split tips?
The factory setup is the Best design for what the company has to work with
namely, sound, power output, needed back pressure...
If lets say you do have a single exhaust and it has a split tip, then it's most likely
for show, although it will still flow a little more exhaust then just the single tail pipe.
I am always amazed at guys with 302's and are running 3" exhaust... etc:
Much can be learned by going to one of the muffler company sites, they usually
have "exhaust flow" charts. Also other sites talk about back pressure, and different
diameter pipes, and mufflers