Tesla seeking to rid its cars of rare Earth magnets

Campbell presented a few slides to show the investors that showed the weight of rare Earth materials used in the company's Model Y motors (which amounted to about 520g worth.

In a subsequent slide, Campbell showed off what Tesla calls its "next generation permanent magnet motor," which did not include a single gram of rare Earths.

Tesla did not indicate which rare Earth minerals they were referring to, but it appears that the culprits are obvious to EV engineers, with fully 500g of neodymium making its way into every Model Y. When neodymium is combined with other elements like iron, the metal can generate an always-present magnetic field powerful enough to move a car as large as the Model Y.

Unfortunately, there aren't a lot of minerals in the world that can have this kind of effect, so a number of engineers and scientists that Wired spoke to expressed doubt that Tesla would be able to pull something like this off.

Is Tesla ditching rare Earths for good old fashion ferrite?

Without neodymium, a few of the experts Wired talked to pointed to old-fashioned ferrite, an iron-and-oxygen ceramic material that has long been used for commercial magnets, as a possible replacement. Unfortunately, it's not known how ferrite, which is about 10 times weaker than the neodymium magnets currently being used, will manage to move a nearly 5,000-pound vehicle using what are essentially large kitchen magnets.

Currently, Teslas are powered by permanent magnets in the rear wheels with the front wheels using externally provided electrical current to generate the required electrical field to turn the wheels.

Sourcing minerals like cobalt isn't just expensive, it's also potentially hazardous, especially for mine workers, and the supply from mines is becoming increasingly unstable.

Well over half of the rare Earths mined in the world come from China, which also processes these minerals into magnets. Some estimates put the number of magnets processed in China at more than 90% of the total world's supply.

Given the political instability around the South China Sea at the moment, as well as a significant amount of saber-rattling around Taiwan, it's easy to see why a manufacturer might get rattled over the threat to a supply chain with no other seller in sight to step in if things get crazy.