Having towed quite heavy with my previous F150, like in the 10k lbs range (Sierra 2500 on a 4k lbs float) I know that the truck will do so with little fanfare, however as soon as you introduce an enclosed trailer or rv of that weight with slab sides, I found the F150 ran out of capacity very quick. The wind loading really took a lot out of the trucks capacity. I towed for 20k kms with my F150 fx4 echo boost max tow crew 6.5 bed so I've got some honest feedback. It can be done, but the super duty line is worth a serious look when you get in the 8k lbs+ range or 30ft + travel trailer! enclosed trailer range.