I've heard of that happening, but he didn't change the suspension or the tire size, just got new tires of the same type.

Wheel wells are mostly the same between 04-08 and 09-14, 15+ is where they changed a bit with the addition of crash bars.

 

Could be the side lugs. Some are much larger than others

 

Something is off as that is the stock size my 14 came with and I'm running 275/60 R20 all terrains (Falken Willdpeak) on stock 2wd suspension with zero rub.

 

I had the same problem with my truck when I had the "Factory" 20"s on. My Ford mechanic, also a personal friend told me that these trucks were never designed for 20" wheels. Ford just stuck them on there to appease the fanboys. I know with my original chrome clad 20's the center bore wasn't even the correct size making it a pain to get the wheel off.

 

OP: what was the solution aside from hacking up your fender well for no reason?

 

That seems strange. The 20s are the same width as the 18s and the tire gives the diameter. So, I don't see how having a 20" rim would matter. Hub size would be an issue, but that also seems strange that Ford would sell an OEM wheel that was different.

 

There's no way that info is correct. You can fit a whole lot of tire and wheel under there without trimming, and even more with trimming. Something doesn't add up with his story.

 

I'm surprised no one really seemed to mention your alignment -- could be that you're out of alignment, and more so on the side that is rubbing which was brought to light by adding slightly larger tires -- thus you began getting some rub. Might want to double check that before you get some harsh irregular wear on your brand new tires.