Not necessarily. I am proposing that we test whether a person driving his own car would be able to notice the difference in performance between different wheel diameters, in a blind test. They would not know what size was mounted, they would just be asked if they felt a difference in acceleration, cornering, road feel, braking, and ride quality when going from a 17 to 18 to 19 inch wheel. I am sure that most would notice a difference in cornering between a 17in wheel and a 19in wheel, but I wonder if the difference in acceleration would be noticeable when doing back to back tests. So, nothing scientific, just perception. I suppose that it would not hurt to measure acceleration as well. So, with a test like this, the suspension setup they have would not matter, since they would only be comparing how their car feels to them, not one car v/s another. Of course, if their car is so low that it creates a clearance issue, then it would be a problem.
Anyway, it is just speculation for now. I have no idea if something like that could even be arranged. I also don't know if I could find enough people to agree to have 3 separate sets of wheels mounted on their car for testing purposes. People can be pretty picky when it comes to things like that.
Maybe whoever is posting on this thread for Modbargins would be interested in helping out with a test like this? How about it? Do you want to come to NC, and help out with a wheel test? Or, you could just send me the wheel/tire sets, and I could arrange the tests, take some photos, and post a thread about it on here. I could send the wheels back when we were done, and you would not have to come to NC. Also, you could get some free publicity!