Hi all I have just completed a 3,600 km trip from Melbourne to the Gold Coast towing our caravan with the 2016 SR5 2.8 D4D, which at the time had only 5,000 km on the clock. I averaged 15.4 ltr per 100 km round trip, this included driving around the gold coast for two weeks.
The best fuel economy I got was about 13.3 on one section of the trip up the Newell highway on the way there, and on the home stretch I got 13.7 along the pacific highway coming back home.
The car performed flawlessly aside from the transmission never reaching 6th gear, but from what I have read on the other posts there is a software update which I will be talking to my local dealership about.
I did use cruise control ONCE from Melbourne to Parks NSW, but it used way too much juice, what I found was the cruise control would obviously change gears more often and rev the engine when ever I approached an incline or hill. Just driving the car normally without cruise control I allowed the car to slow down on hills ( speed dropped from about 110 km to about 100 ) this obviously used a lot less juice.
The caravan weight all up was about 2,200 kg's, two adults an two children, car was full of kids stuff, toys, DVD players, I pads etc. The rear tube was full with, two tables, 5 chairs three scooters, tarps, I think that was about it, I'll try and post some picks.