Battery electric vehicles (BEVs) have advanced significantly during the past decade, yet drivetrain energy losses continue to restrict practical range and elevate cost. A dataset comprising more than 1000 European-market BEVs (model years 2010-2025) is combined with detailed inverter-motor co-simulation to chart technology progress for and quantify the efficiency and cost-saving potential of partial-load optimised multi-level inverter (MLI) for 2030. Average drive-cycle range has climbed from 135 km to 455 km, while fleet-average energy consumption has remained virtually constant. Three inverter topologies are assessed to evaluate future efficiency and cost enhancements: a conventional two-level (2L) six halfbridge (B6) inverter with silicon (Si) and silicon carbide (SiC) devices, and two three-level (3L) T-type neutral point clamped (TNPC) and active neutral point clamped (ANPC) inverters tailored for partial-load operation. The 3L-TNPC inverter, realised with only 30% additional SiC chip area, lowers drive-cycle drivetrain losses by 0.67 kWh/100 km relative to a SiC 2L-B6 baseline. These results identify partial-load optimised MLIs as a cost-effective route to further reduce BEV energy consumption and total system cost.