BMW is testing a new type of in-wheel electric motor technology which features dual rotors and could be used to improve the efficiency and range of its electric cars. With further tests set to be carried out in the coming months, let’s start with a quick breakdown of how the system works. Don't worry, you don't need a physics degree to understand it, either. It’s been built by Munich-based tech brand DeepDrive, which created a compact solution where two electric motors can be merged into one. The trick here is that, while conventional electric motors move either the internal or external rotor, DeepDrive’s creation can move both simultaneously. Result? Better performance and economy… supposedly.