BigDaddy 2 said "on Dodge or Chevy from personal experiences with the 6L motors....but the fords I have driven are horrible on fuel consumption (lucky to get 350kms on a tank not pulling a trailer), under powered, uncomfortable ride, and takes about 3/4 miles to turn around. Now I must admit, the newest 3/4 - 1t fords I have driven was a 2015, so maybe they've changed a little, but I doubt it. Just pulling a 4500lbs trailer up the north hill is a struggle to get up to speed without being right to the floor. Maybe all the trucks I've driven (and I've driven lots of different fords) were all lemons, but you couldn't give me one for more than a day before I traded it off.
I've only heard good about the new Chevy's (but most of my friends and myself are chevy fans). I've heard good comments about the new dodge gas trucks too. "
If that's the case getting less than 350km to a tank get that truck to the shop because theres something wrong. I've had a 2015 f250 with the 6.2l gas engine and could do 600km a tank all day.
Also have a 2017 with the same engine and no problem getting similar fuel economy.
To the person who said these new aluminum trucks are too light, I cant speak on the 1/2 tons but with the 2017+super duty models they are actually heavier. Dont believe it, scale them sometime. Many on ford Forums have done so and came in 100+pounds heavier with the newer trucks. Possibly do to the redesigned boxes steel frame.
This is an important question to the OP...what is the tongue weight and overall trailer weight when loaded. This should be a starting point where to look for new truck. I can't imagine your 35'travel trailer is going to be under 9k lbs loaded with gear not to mention weight in your truck as well as passengers. 3/4-1ton market may be the better option over 1/2 ton depending on weights.