I've got a '16 F-150 XLT Sport 5.0, 3.55 Locker, Trailer Tow Pkg, 36 gallon tank, short box and 18" tires. Our yellow sticker shows 1939# payload, which I was pretty happy with. From the dealer it had the Appearance Package with the 18" tires, P metric, passenger car tires.

I drove 18-wheeler for 20+ years, and about 3 million miles, so I've pulled a few trailers, but there was a learning curve pulling a travel trailer. My 2001 F-150 had brake issues, so that was the big reason we got the new truck. We also have a '16 Jayco TT that has a gross weight of 6500#. Before we got the '16 truck, we made a trip with our '01, which had 10 ply LT tires, and it pulled the trailer fine. With the new truck, with the P metrics, it had a SQUISHY ride. Once I got the 10 ply tires on the new truck it made a world of difference.

In April we took an 1800 mile trip with our Jayco, and had no problem at all. This was up in the hills of northern Arkansas, Missouri, and up into Kansas. With the 5.0, and the 6 speed it was a DREAM pulling the trailer.

The biggest drawback with the LT tires is the air pressure. These tires are rated at about 3400# load E rating and 80 psi max pressure. I have to air-down to about 38# around town, because the ride gets rough with the truck empty. When I pull the trailer, I air up to 75# on the rear, and 65# in the front.

We have also been looking at an upgrade trailer, and it has a gross weight of 8100#. That would be about the MAX weight I would feel comfortable towing with our truck. Look at charts, you find several different towing capacities, depending on what options are on the truck. Depending on WHICH chart you look at, the new trailer can be 1000 or more than 3000# under the max towing weight.

I've always wondered HOW a 3.5 Ecoboost truck, with similar options, has a 12K tow rating, and a 5.0 motor, have about a 9100-9200 pound rating?? If your looking to pull a 10K trailer, an F-250 would be the MINIMUM that I would consider, and definitely go with a diesel. Even a big gas motor wouldn't have the durability needed to pull a load that heavy consistently, without having a lot of internal engine wear. If it's a couple times a year, and a few hundred miles each trip, you can get away with a more NORMAL truck set-up. We've been looking at possibly going full-timing in our RV, so we're going to be putting a decent amount of towing miles on the truck.

 

Thank you for you many years of carrying what we need/want to where it was needed/wanted over the road!

You answered your own question wondering how an EcoBoost could pull more than the "big V-8" in the F150.
It is the same way a diesel pulls better in the 250-350's and up. Some diesels pull better than others but that is a discussion for another board.

The peak torque of the EB is 2900 RPM's and the peak torque of the 5.0 is about 4300 RPM's.

The 10 speed transmission in the new F150 helps and I am confident that it will make its way into the rest of the F150 line in time.

 

Since my original post, I added the Hellwig rear anti-roll bar and Firestone air bags. I've pulled my TT on a couple of short trips before and after, and it definitely seems more stable and has less porpoising. I'm taking it on my first longer highway trip tomorrow, so I'll know how it compares to my previous, bigger truck better after that. My expectation is that it will be quite comfortable at 60 or 65mph, but not any faster. I could go faster with the 3/4 ton diesel truck, but probably shouldn't have been. :-)

I haven't replaced the P-metric tires, but may consider that as well. It's just that 99% of the time, I'm not towing.

 

Ford added another 1000# towing for the 2018s, to 13,200#.