Overview
- The RWTH Aachen benchmark, published this week in the journal Energies, analysed 115 electric traction motors from 80 vehicles dated 2019–2025 to map design and manufacturing trends.
- Researchers found core architectures are similar across China, Europe and the United States with the main differences in material choices and component implementation.
- Gravimetric power density for permanent‑magnet synchronous motors rose about 45 percent from 1.68 kW/kg in 2019 to 2.43 kW/kg for 2024–2025 models driven in part by many motors running near or above 20,000 rpm.
- Chinese makers increasingly use magnesium‑alloy housings that can cut housing weight by 20–30 percent while Europe and the U.S. more often use aluminium, a shift that raises concerns because cited data show China supplies a large share of primary magnesium.
- The study also documents wider use of direct oil cooling and tighter motor/gearbox/electronics integration, notes higher sealing and manufacturing demands, and cautions that its sample is systematic not statistically representative so it cannot deliver controlled efficiency comparisons.