This paper presents a methodology for the optimal co-design of an inverter and machine to enhance energy efficiency, considering the WLTC class 3 driving cycle. In the 800V system, a 3-level ANPC inverter and silicon carbide power devices are employed for the inverter design. These not only reduce energy consumption during the driving cycle but also significantly impact machine design parameters. A case study for an 800V traction system with a delta-shape IPMSM is presented. To optimize the inverter switching frequency, PWM strategy, and machine geometry, the DOE method is utilized, combined with FEM analysis. The results demonstrate an improvement in total energy loss during the drive cycle.