What is the real reason that the 2011 F150 Harley-Davidson AWD has a much lower towing capacity than the other F150s of the same year. There is the 6.2L, 3.73 final drive, the trans is solid. Does it come down to 22 inch wheels with low profile tires. I'm hoping someone knows the real answer.

I think your right. Low profile tires wouldn’t have the same load capacity as big fat tires. No doubt you can pull a 9,000lbs trailer. But loading a tonne of dirt in the box will likely blow the tires