[JWreck]

It looks like it sits higher on 20" wheels because it's an optical illusion. You notice the gap between the wheel and fender easily, but your mind doesn't see the tire that is taller on 20" wheels.

 

[JWreck]

Not correct, every single measurable performance metric gets worse as you go larger in diameter. This is a well known, well documented, fact that cant be argued away because physics works. C/D tested this exact car in both configurations showing those results while surprising absolutely no one because the math cant be circumvented. This despite having the weaker all-season rubber. Had the 20s been shod with similar rubber rather than the weaker all-seasons the 22s would have simply been beaten by a larger margin because there can be no other result. Similarly if you stepped down to 19s of similar construction and ran them with the same rubber they would outperform the 20s. This is why all the track rats over on the M3 forums, corvette forums, etc downsize from factory and you see the threads titled "Which 18" wheels will clear "X" brakes?" They do it because unsprung weight is a killer. Just to frame it in another way, stepping up from 20 to 22s is going to add about 10 lbs of unsprung per wheel with a wheel of the same type and brand. That is equivelent to duct taping a 10lb barbell to each wheel because the extra diameter serves no purpose, it's nothing more than extra weight that must be started in motion, kept in motion, stopped, turned, and suspended. And you t hink this is going to be a good thing how?

I get that some like larger wheels for the look. I'm fine with that it's their money and their choice but a lot of people on this type of forum are not aware what they are losing by choosing them in some cases this is because of information such as what you posted which is not correct. OEMs put them on cars because people like the look and wheel options are a huge profit item with high uptake. I'm not completely immune to it myself, I think those E92s with 18s look a little odd and it's not a choice I would make. I would be making that choice understanding it though, not in ignorance. It's all good if you go in eyes open.

While this is accurate for the issue at hand, remember it isn't a universal rule that applies proportionally. EX: If you put 14" wheels on the F Pace, it will likely (read: surely) handle worse than 18" or 20", for many reasons.