Why is unsprung weight so important? Ask the people who make their money at it, the race car engineers. Reducing unsprung weight will improve acceleration, braking, just about all aspects. The exotic race cars have ultralight wheels, tires, move the suspension springs into the body and operate them with rocker arms and linkages. They have carbon fiber brake rotors and try everything they can to get rid of unsprung weight.
I have seen many “formulas” that claim getting rid of a pound of unsprung weight is the same as getting rid of 100 pounds of sprung weight that may not hold up to scientific scrutiny, but there is truth to the fact that unsprung weight reduction pays off.
So what does all this have to do with tires? As you go to wider tires guess what? You can increase your unsprung weight. Wider tires will require a wider wheel. Changing to a larger diameter tire will require a different wheel as well. So while you are looking at all those choices in replacement wheels try to find the lightest wheel you can afford. Unfortunately the sources for aftermarket wheels don’t generally make wheel weight easy to find out. I find that Tire Rack (
http://www.tirerack.com/) does have that information for most of the wheels and you can call them directly if it is not listed on-line.
