These days, carmakers are in a bit of a quandary. For generations, the industry has evolved and refined its products, and now it’s time to throw away that knowledge as it pertains to internal combustion technology and learn all new things about electric powertrains. This feeling must be particularly acute in the more specialized corners of the industry, like the go-fast merchants responsible for those factory-built, souped-up sedans and SUVs with badges that read AMG, Blackwing, and the like.

BMW M is arguably the most famous, having just celebrated its 50th anniversary this past week. For decades, since the mid-engined BMW Turbo concept of 1972, the tricolor badge has been a byword for sharp handling and plenty of power, usually delivered by a peach of an engine. But the future is electrified, even at M, which is why we were in Berlin to try out its latest creation, a tweaked version of BMW’s latest electric SUV, the 2023 iX M60.

We had our first taste of the iX last summer. It’s a controversial-looking thing, as with so many of BMW’s more recent creations, and it’s best thought of as an all-electric alternative to the more conventional X5 SUV. But the engineers at M have now gotten their hands on the iX, having already worked their magic on the i4 M50.

Electrification is a bit of a double-edged sword for outfits like M. Electric motors might not be mellifluous like some of BMW’s six-cylinder engines. But even the sharpest naturally aspirated engine can’t hope to match the immediacy of an electric motor when it comes to instantaneous throttle response, particularly in the 0–40 mph (0–65 km/h) speed envelope within which most of us spend most of our driving time.

On the other hand, these kinds of powerful electric motors only work if you can supply them with high-voltage electricity, and that currently means lugging around enormous lithium-ion battery packs that, all told, weigh several hundred pounds more than an equivalent gasoline-powered powertrain. The iX M60 has a curb weight of 5,769 lbs (2,617 kg), which is about two middle linebackers more than the BMW X5 M, realistically the iX M60’s closest internal rival in terms of price and power output.

Going electric means carrying around a little more mass, then. BMW has added more power to compensate, but the mechanical changes to the powertrain compared to the less powerful iX’s we drove in 2021 are minimal.

The rear motor has had its rotor lengthened by 0.8 inches (20 mm), which allows for a larger magnetic field to be applied—and therefore more power to be generated. The motor spins to 15,400 rpm, and there’s now a six-phase double inverter that allows for a maximum of 1,200 A, which is transferred to the wheels by a single-speed transmission that’s housed within the same compact drive unit as the motor and power electronics.

As with BMW’s other Gen5 electric drive units, it’s made in-house and is an electrically excited synchronous motor that uses no magnets (and therefore no rare earths) in its construction.

The headline figure is the iX M60’s combined 610 hp (455 kW) in sport mode and launch control and 811 lb-ft (1,100 Nm) of torque available in launch control. And since the iX M60 doesn’t need to spin up turbochargers or fill 4.4 L of a V8 engine with fresh air, that gives it a natural performance edge over the X5 M. Zero to 60 mph (97km/h) takes a mere 3.6 seconds, and the top speed on summer tires has been increased to 155 mph (250 km/h).

In the iX M60’s less frenetic drive modes (Personal and Efficiency), the power delivery is mapped back a little to a maximum of 532 hp (397 k) and 749 lb-ft (1,015 Nm). Individually, the front drive unit is rated at 255 hp (190 kW), and the rear is at 483 hp (360 kW).

https://arstechnica.com/?p=1856074