acdii

I have towed the same trailer, a 2000 Trail-Et New yorker 2 horse trailer with a 2001 F150 with the 5.4, and the same trailer with a 2013 Flex with the 3.5L Ecoboost, and the Flex had more pulling power. The 2012 F150 with EB I also pulled this trailer with and it didn't even know it was back there. I have a smaller 6x12 enclosed single axle trailer that I pulled through Iowa and several times last year to my flying field, and also one time fully loaded up from Home Depot with sheetrock, plywood, lumber and shingles, it was maxed out, yet the truck just pulled like it wasn't there.

The EB has an advantage over the 5.0 by producing max torque from 1500 RPM, where the 5.0 is more up in the 3000 range(maybe higher, too lazy to look it up).

On the MPG side, no clue what the 5.0 does, the 5.4 was about 8, and the EB is about 13. I did pull this same trailer with a 97 Explorer with AWD and the 5.0 V8 based off the 302. The EB definitely has more power over that engine.

Either way you decide though, they are both good engines, I prefer the EB since it gets better MPG for my needs then the 5.0 can, the 5.0 might get slightly better MPG while towing, but as always YMMV.

Edit: One thing I forgot to mention, the 2012 had Max Towing package with 3:73 gears, my current 2014 F150 RWD Screw has 3:15 gears. Even with 3:15 it pulls nicely, not as much dead stop giddy up and go with a trailer, but still pulls with ease.