Originally Posted by ILC32
If you go to 18s the tires will be lighter as well, I believe. And you would be reducing unsprung weight . . .
Why would tires be lighter? To keep the same rolling diameter the tires need to be bigger, i.e. higher sidewalls. This makes the tire heavier. What is wanted is lighter wheel and tire combo. Smaller wheel, heavier tire and vice versa. Going to smaller wheels does not automatically make the combo lighter.