Q: Does a lighter forged wheel like the UP-04 actually improve performance?

Yes. Reducing unsprung and rotating mass directly helps acceleration and braking, plus energy efficiency, because the motors and brakes have less mass to spin up and slow down. The UP-04 gets there through forged aluminum, weight-optimized spoke shaping, center buttressing, and stepped machining. Weights start from 19.1 lb depending on size. It is a measurable benefit on a heavy EV, a real gain you feel most in stop-and-go driving.