My 2007 Tacoma V6 4X4 Auto transmission.. The Owners manual recomends that I TOW in 4th gear....NOT Overdrive 5th. This drops my gas mileage to about 16+ highway mpg.
Normal MPG for me on this truck is 22 Highway.
I wish I still had the Tacoma STICK. I used to get 22mpg going
over the mountains to Rutland with this same boat, towing with a 1995 Tacoma V6 4X4 (190HP) ....STICK Shift. Just Sayin..

NB