Overview
- The peer‑reviewed study published on November 11, 2026 examined 115 electric drive units from 80 vehicles spanning model years 2019–2025 and found the basic motor architecture is the same in China, Europe and the United States.
- Since about 2022 the sample shifted toward highly integrated units that combine motor, gearbox and power electronics into smaller packages, a change that favors compact designs and simplifies some assembly steps.
- Gravimetric power density for permanent‑magnet synchronous motors rose from about 1.68 kW/kg in 2019 to 2.43 kW/kg for 2024–25 models, and many newer motors now run at 20,000 revolutions per minute or more with outliers near 30,500 rpm.
- Cooling designs are moving away from classic water jackets toward direct oil cooling of rotor and stator, a change that improves heat removal but raises demands for seals, precision casting and tighter production tolerances; in the 2025 sample only six of 13 motors still used classic water cooling.
- Material and component choices remain the main differences between regions, with some Chinese makers using magnesium housings and powder‑coated busbars and European firms favoring aluminum and complex copper‑in‑polymer busbar assemblies, a split that affects weight, cost and supply‑chain risk because China produces most primary magnesium.