Unsprung weight is an important factor in a vehicle's performance. The lighter the wheel the better the acceleration, handling, and braking. I've been working with Japanese tuners for several years already and one thing that Jun & Toda have taught me and have actual studies conducted on this subject, is that for every kilogram you lose in unsprung weight is equivalent to 15 kilograms in sprung weight off the car.

For example, I used to have 17" Tenzos on my 2001 MR-S which weighed 19.5lbs........later I swapped that with RH Evolution CP8R 17"s that weighed in at 12.5 lbs. Losing that 7lbs was equivalent to losing 190lbs off the car.........nearly 10% off the curb weight of the vehicle.

If you're really into performance, as I am, and want the look and performance, then go with forged 1-2 piece rims...........they're the strongest and lightest next to magnesium wheels. Expect about $700+/piece for forged 19"s from Japan. Magnesium wheels cost about $1500-$2000/piece.