My V10 F350 dually gets 7.5 mpg towing my 6500 lbs loaded travel trailer. I imagine that it would get the same no matter what weight TT or fiver is behind it. I personally believe aerodynamics play a bigger part on the MPG of the V10 than trailer weight.
Empty... 9-11.5.mpg... depending on the time of the year... depending on how I drive it.
I had a 97 F150 I towed the same trailer with. I think that was about max for my F150. Did ok, fairly comfy, but spent a lot of time at 3500 plus rpm's.
The V10 is a towing beast...
Thanks!
Jeremiah