M-Fünf said:
Rotating mass will degreade performance. A heavier wheel with lighter caliper would still degrade performance since the caliper is not rotating mass, only the wheel/tire/rotor, and all of those are getting bigger...
Right?
Yes, but the Calipers are still lowering UNSPRUNG Weight. That is important for handling.
Taking 1 lb of unsprung weight off is worth taking 10 lbs of sprung weight off.
The other issue is, 19 and 20 inch tyres are heavy. Don't jump to the conclusion that because they have a smaller side wall, they are lighter. They're not. So even the tyres are adding unsprung and thatis not desireable.
Beyond 18 inch, you have gone past the point of diminishing returns. They make uber light, uber strong 18's.
That kills everything 19's have to offer.
19's and above are purely cosmetic. Granted, alot of them look good.
The question is, do you want your car to look great whilst you stand next to it, or would you prefer it looking good as you four wheel drift past someone in a corner?
The age old question of, Performance/Practicality Vs Looks.
MJ