That unsprung weight is literally at the roll center of the car so the effect on handling is negligible. If that's really the concern get some aluminum 17-18" wheels and 35-40 series tires, way more bang for the buck in reducing unsprung weight in a useful way. Also it'll be a massive improvement in handling and steering feel and response over 15" steel wheels with fat mushy 60-series street cruising radials. I know because I've run both setups lol.
