Abstract:
According to Electrek, Tesla CEO Musk recently confirmed on the
It is reported that the cause of the incident was that Tesla investor Sawyer Merritt disclosed the technical parameters of the Cybercab drive unit on the X platform after the Cybercab launch conference in Austin on September 3.
Musk personally forwarded and confirmed the core message of "zero rare earths, unchanged battery life". According to Merritt, the Cybercab drive unit uses a simplified version of the hairpin stator and a new lubrication system, which is 18% smaller and 25% lighter than competing products at the same level. The motor has a rated power of 163kW and a 47.6kWh battery pack with a range of approximately 673 kilometers.
Traditional electric vehicle permanent magnet motors rely on neodymium iron boron magnets to provide strong magnetic fields. Taking Model Y as an example, a single motor uses about 520 grams of rare earths. The core difficulty in maintaining the same battery life without using rare earths at all is that the magnetic force of alternative magnetic materials is only seven to one-tenth of that of NdFeB.
According to industry disassembly analysis, Tesla’s solution is a combination of punches: the Halbach array magnet arrangement is used to concentrate the magnetic force on the working side, maximizing the reluctance torque ratio. The hairpin stator increases the copper wire trough full rate from about 40% to 70%, and at the same time increases the motor speed to a range above 15,000 rpm.
In terms of cost, rare earth permanent magnets usually account for 25% to 35% of the total cost of motor materials. Removing rare earths is expected to save about a thousand US dollars for a single drive unit.
The deeper motivation lies in supply chain security. About 90% of the world's rare earth refining and processing is currently completed in China. After China implemented export controls on medium and heavy rare earths in April 2025, Musk has publicly admitted that the mass production of Optimus humanoid robots has been hindered by rare earth restrictions. Cybercab rare earth-free motors essentially replace physical solutions with geophysical solutions.
However, the motor is currently only confirmed to be installed on the Cybercab two-seater car with a curb weight of 1,412 kg. It is still doubtful whether it can be adapted to high-power models such as Model Y and Cybertruck. Rare earth-free motor suitable for all car models.
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