Lower profile tire might make the vehicle a bit more skittish by raising the effective spring rate due to less flex in the sidewall.

Does the factory do anything to compensate the suspension on trucks that are otherwise similar except for being delivered with 20s on them as opposed to 17s.

 

Nope, other than lighten the wallet of the driver.

 

For the same reason they make multiple 17", 18", and 20" rims for different packages. For the same reason some people go out and buy aftermarket rims. For looks. I love the look of my 20" rims

 

Yeah, that's what I figured...lol

 

The sidewall on the 20" F150 tires isn't near as narrow as on the Harley 22".