I had a 2013 SuperCrew with the 5 1/2' bed. I absolutely loved the truck. It had the 5.0 V-8. I could get about 18 mpg average. Pulling a 2700 lb tent trailer, it was 14 to 15. The truck had a total payload of 1700 lbs. With the wife and I in it, you're left with 1400. With the tent trailer tongue weight, it was down to 1100. Add all the stuff we carried in the truck bed (extra water, tools, compressor, Engel refer, etc.), and it was down to 500.
The real problem came when I got the itch for a popup camper. I considered the FWC Hawk, probably the lightest you can find. A base Hawk has a dry weight of 1075 lbs. Add water and LPG and you're at 1260 lbs. Now, add the solar panel, leveling blocks, camp chairs, etc., I have in/on my tent trailer, and there's another 150 lbs or so. We're now up to 1410. As soon as the wife and I climb in, it just went over capacity. Oops, I forget that I'm going to need that 75 lbs of tools and compressor, the two 25 lb packs of clothes and survival gear we carry, the Zodi shower, the porti-potty, sleeping bags, extra water, food, utensils,.......... One day, I actually weighed everything we carry. I almost passed out when I saw the total. At best, we would be about 600 lbs overweight. Even worse, it's all on the rear axle. I knew there was no way the F150 was going to do the job. As a result, there is a gas guzzling (6.2L gas) F350 crew cab long bed in the driveway now. It can carry 4400 lbs. What a beast. It's 3' longer than the F150. Mileage? Don't even ask. There's a reason it comes with a 48 gallon tank. I know, you're wondering... unloaded, about 14.5 highway, and 11 in town. In both cases, driving like grandma.