anyone tow with f150 with 3.7 v6?

Agree with APT !

I moved from a small F150 V8 to a larger F150 V8 to feel comfortable pulling a smaller TT than you have. My mileage generally is 13 miles per gallon while pulling and 20 without on freeway. You may not be very happy if you "nickel dime it".

I would not bother. While the 3.7L V6 has more peak power than many V8s from 10 years and and the 6-spd trans far better than the older 4-spds, it will be operating at what most people find an unacceptable engine speed range. Towing any high walled RV requires a lot of power to maintain 65mph due to aerodynamic drag.

Frankly, the fuel economy differences between the V6 towing and around town are minimal, less than 10%. The power is significant.

you should really compare the mpg ratings instead of assuming a v-6 truck will get better gas mileage than a v-8 truck.

i assumed the same thing until i started researching it. found out a modern v-8 truck will get virtually the same mpg as a v-6 truck.
and carry more passengers, cargo and tow capacity.

for example, the Honda Ridgeline gets almost the same mpg rating as my Chevy Avalanche.
the Avalanche can seat 6 adults vs. 5 for the Honda, carry way more cargo and have over a ton more towing capacity.

or another example:

my 2007 Avalanche's mpg: 21 highway/15 city
2007 Nissan Frontier's mpg: 20 highway/ 15 city

Don't own one but have heard very, very good things about the 3.7L, both power-wise and economy-wise.

Don't have the output numbers handy but chances are it has more HP and nearly as much torque as V8's from a generation ago.