BMW ships a motor with no magnet in it
BMW confirmed on July 17, 2020, that its current electric motor needs no rare earth material at all, in a statement relayed by a trade publication that covered the announcement directly. Most electric motors turn the rotor, the spinning part of the motor, using a fixed magnet built into it. BMW instead feeds electric current straight into the rotor through brushes, sliding metal contacts that carry current onto a moving part, so the rotor makes its own magnetic field instead of carrying a built in one. BMW calls this its fifth generation electric drive, first built into the BMW iX3 in China. A peer reviewed 2024 review of motor technology, published in the journal Materials, independently confirms the same brush fed design and states plainly that BMW is going the other way while most of the industry still relies on a fixed magnet. The design belongs to a family called the wound rotor synchronous motor, and the only other carmaker confirmed building one, Renault, targets the end of 2027 for mass production, with its version still a prototype today.
By 2022, in Dingolfing alone, we will be able to produce e drives for more than half a million EVs per year.
Oliver Zipse, chairman of the board of BMW Group. Source 3.
What going magnet free costs
No source here tests the magnet free motor BMW ships today against a magnet containing motor of similar size on the same bench. The closest sourced answer comes from elsewhere, an engineering study General Motors carried out with Oak Ridge National Laboratory, funded by the Department of Energy. It built and bench tested 3 real motor variants at the same 350 volts, and every number below is from that study, not from BMW. All 3 were designed to use no heavy rare earth elements, but only 1 removed every magnet completely, an induction motor built with copper bars in the rotor and cast aluminum rings at each end. The other 2 still carried a permanent magnet, a smaller one or one built from lighter rare earth material.
All 3 variants in this study were designed to use no heavy rare earth elements. Only Variant 3 carries no magnet of any kind. Variants 1 and 2 still carry a magnet, a smaller one or one built from lighter rare earth material. These are bench figures from a Department of Energy funded study, not figures from BMW.
Show the numbers
| Variant 1, kept a full sized magnet | 4.1 |
| Variant 2, kept a smaller magnet | 3.15 |
| Variant 3, no magnet at all | 3.2 |
The fully magnet free variant produced 3.2 kilowatts of power for every kilogram it weighed, against 4.1 kilowatts per kilogram for the variant that kept its full sized magnet, about 22% less, a figure calculated here from those 2 numbers. It also ran at 92% peak efficiency, the share of electricity a motor turns into motion rather than losing as heat, against 96% for the variant that kept a smaller magnet, a 4 percentage point gap calculated here from those 2 figures, in the same direction the study itself describes.
Same 3 variants and the same study as chart 1, tested on the same bench at the same 350 volts. These are not figures from BMW.
Show the numbers
| Variant 1 full magnet | 22.1 |
| Variant 2 smaller magnet | 14.1 |
| Variant 3 no magnet | 16.3 |
Power density, how much power a motor packs into a given size rather than a given weight, showed the same gap. The fully magnet free variant reached 16.3 kilowatts per liter, against 22.1 kilowatts per liter for the variant with the full sized magnet.
Why any of this is being tried
The European Commission projects that demand for rare earth metals across the European Union will grow sixfold by 2030 and sevenfold by 2050. Its Critical Raw Materials Act, in force since 2024, sets requirements meant to push more recycling of the permanent magnets already in circulation. A motor that needs no magnet at all sidesteps that growth entirely, at the cost the government funded study measured.