BMW is testing a four-motor powertrain for future M performance EVs, the automaker announced Wednesday in a press release.
The automaker has already introduced diet M Performance i4 M50 and iX M60 models, but not a dedicated electric M model that pulls out all the stops. The prototype powertrain—revealed an i4 development mule—hints at what could power the first of those models.
BMW said it's testing both the powertrain and a related chassis-control system that helps better distribute power, the automaker claims. The infinitely variable torque distribution of electric motors allows a lot of flexibility, BMW noted, saying that the system measures output from sensors, as well steering angle and accelerator pressure, to apply the optimal amount of power.
2022 BMW i4 M50
The i4 M50 development mule uses some elements from the gasoline BMW M3 and M4 (which share the same platform) to improve cooling and torsional rigidity, as well as to make space for the four motors. Two motors power each axle, meaning each wheel gets its own individual motor.
BMW's use of a four-motor powertrain for a performance EV isn't an efficient approach; it adds extra weight; and it's fairly novel, as many other manufacturers are maxing out at three motors. Lucid has been developing a tri-motor version of the Air, and Tesla puts three motors in the Model S Plaid, although the Plaid+ which supposedly maximized acceleration from the layout has been effectively cancelled.
The GMC Hummer EV uses three motors as well, which is enough to get the roughly 9,000-pound truck from 0-60 mph in 3.0 seconds with "Watts to Freedom" (WTF) mode. And three-motor Audi E-Tron S versions are available, but they're rare and we haven't had any opportunity to drive them—let alone go back-to-back with the dual-motor versions.
2023 BMW iX M60
Rivian offers a quad-motor powertrain in the R1T pickup truck and R1S SUV but hints that the layout is very expensive to build—though it's teased special Tank Turn and K-Turn modes with it. Tesla has also promised a four-motor version of the Cybertruck, while the Lordstown Endurance is slated to use four in-wheel motors.
So if BMW's quad-motor powertrain makes it to production in a future M model, outside of exclusive supercar makers like Rimac it could be the first of its kind aimed at canyon roads and racetracks rather than job sites and off-road trails. Stay tuned.