BMW XM Prototype Review: The Hybrid Future of M Is So, So Good

If you follow BMW news enthusiastically, you’ll know this car has been spotted, camouflaged up, and speculated as being something along the lines of an “X8,” a perhaps larger version of the X7 before the XM concept was formally introduced in late November of 2021. It’s sort of like a hypothetical X8, sure, but if you were expecting a big car meant simply to make the Bavarian automaker’s growingly garish lineup a bit glitzier, you’re wrong.

It doesn’t appear like that on the outside though, to be fair. The exterior styling has BMW’s modern big grille sensibilities combined with all the subtlety of an armored personnel carrier. Yes, the XMs we drove were heavily camouflaged, but they clearly resembled the concept car previewed several months ago. The interior is a different story, though. You won't be surprised to find it only loosely resembles the concept; however, the second-row seats—the XM has no third-row—are something special. It’s more like a couch back there than anything else on the market, with the outside bolsters extending all the way to the C-pillar. This admittedly functional design translates into an incredible amount of space for two rear passengers.

My short time with a prototype XM all started with an introduction to the car’s various systems, of which the drivetrain was central. The car’s all-new V8, which BMW only gave me hazy details of, works together with an eight-speed transmission-mounted electric motor to send around 643 horsepower to all four wheels. A more powerful, 740-hp version of this drivetrain is expected later on, but for now, the 600 and change was plenty. 

Yes, this car is a hybrid, and a good one at that. The V8 provides the melody, but the bass is brought in by that powerful electric motor. In short, the combination makes the XM drive like a total freight train. Punch the throttle pedal and the electro-mechanical beast takes off no matter the context. Gear after slammed gear; the XM kept pulling and pulling hard.

The only limiting factor to my testing was the pouring rain that hampered our hour-long drive around Salzburg, Austria, located within driving distance of the automaker’s M development center in Garching, a suburb of Munich, Germany. As a result, really testing the car’s cornering was hit-or-miss. But what was clear was that the high-power hybrid system enabled much better handling for a big car than was possible before, as explained by the engineer in charge of the vehicle’s driving dynamics, and who was riding shotgun. The 48-volt architecture means the active sway bars, which are located on both the front and rear axles, can adjust the suspension to the most ideal comfort or performance levels. This translated into a large, heavy SUV that, despite its massive power, legitimately felt nimble to maneuver. Good steering, with more than adequate road feel and well-blended regenerative braking, also helped make everything feel natural and genuine, even if it was all carefully orchestrated by a slew of software.

The XM also gets help from a few degrees rear-axle steering and active magnetic dampers. But it uses conventional springs as opposed to air springs to get the job of, uhhhh, suspending done. This is unlike other sporty SUVs like the Aston Martin DBX or Lamborghini Urus, however the friendly BMW engineer sitting next to me—in between discussions of American lobster prices and how he could easily get out of a speeding ticket on the Interstate by playing dumb—insisted this was the right way to go. Steel coils work great in BMW’s current stable of M products, and that’s no different here. Indeed, that’s really the story of this car: a lot of classic M methodology being applied in a way it hasn’t been before. That’s mostly because of the addition of the relatively simple plug-in hybrid system, which totally changes the game.

Unlike other automakers' systems, there’s no dedicated electric axle or complex network of electronic gizmos mounted to the engine. BMW has taken a much more straightforward approach. The electric motor is simply mated to the transmission—much like in its regular hybrids—and located inside the same housing. That means it can be mounted to the back of any number of engines or have a conventional transfer case bolted to it, like in the case of the XM. As such, electric power can be delivered anywhere the combustion engine can send it, either independently or at the same time.

As a result, the total system output of 643 hp is only achievable when both the engine and the electric motor are working together, however you can have one or the other. BMW was cagey about both the electric motor’s power and the battery’s size in kilowatt-hours, but the XM has roughly 50 miles of electric-only range on the European WLTP scale. Likewise, while an exact power figure wasn’t given, the XM felt faster in EV mode than a new Chevy Bolt, which likely translates to more than 200 hp on the motor side.

The impressive part of the XM wasn't just the individual parts, though. It was how they all added up. The XM’s hybrid system doesn’t just add power, it enables a lower center of gravity than the current X5 M. Just the same, the regenerative braking allows for gains in efficiency that make cars without it seem prehistoric by comparison. Instead of turning braking energy into heat, the XM saves it to prepare for that next impressive pull down the highway. From a standstill, the XM will pull away well using only electric power whether or not the combustion engine has anything to say about it. The way the drivetrain works is just plain impressive. It solves issues pure ICE cars have, such as using up gas while idling, while letting the engine do its thing. You get a twin-turbo V8 and another electric engine to complement it. What’s not to like?

After driving this thing, it is clearer to me than ever that PHEVs are the hopeful future of performance cars. Reading in between the lines of BMW’s future M plans—which involve this plug-in hybrid SUV and not any of the current crop of all-electric cars—I’d say the Bavarian automaker and I agree. For example: The highest trim of the i4, an all-electric sedan with more than 500 hp, could reasonably be called an electric M3. Sure, a few tweaks would be necessary, but the makings of one of the brand's bread and butter M cars are there. BMW M's VP of customer, brand, and sales, Timo Resch, agreed when I asked him about this—but clearly, it’s not called a full M car for a reason. That led me to a simple question for Resch: With today's technology, would you rather have an electric M3 or no M3?

It didn't take him long to consider this question. "No. No M3," he told me. Until the technology is ready, BMW isn't going to risk one of the most well-known performance brands in the world for the sake of optics, even in the face of cars with four-figure horsepower like the Tesla Model S Plaid or the Lucid Air. So, given that the XM has M in its name and there isn’t an M i4 yet, that makes Resch's confidence in hybrids obviously quite high. Also, consider that it's quite likely that some version of the drivetrain from the XM will find its way into the next-generation M5. Likewise, I have no reason to doubt the technology will filter down into the rest of BMW M's lineup in the future, with other BMW employees hinting that a similar hybrid system will almost certainly find its way into the Bavarian company's iconic inline-six. 

So if you're worried about the future of M, put your mind at ease. It's silly to argue that this tech is just too heavy and ungainly to work on anything besides an SUV like the XM when cars like the McLaren P1, SF90 Stradale, and BMW's own i8 exist. What's changing now is that the cost of entry for performance hybrids is slowly going down, and fantastic machines that once stickered at colossal sums of money will soon be far more affordable. 

That being said, the XM is set to be far from the everyman's hybrid performance truck—BMW expects it to compete with the Mercedes G-Wagen and the Lamborghini Urus—but it's paving the way for a future of the brand that we can all be happy with. I understand people’s reservations about the cost and weight of PHEVs, but we have to see the wider picture: battery-electric performance cars can impress with nuance, too. True, they’re about big power, hard launches, and curb weights measured in multiple tons; the cars enthusiasts have traditionally loved—your E30s, air-cooled 911s, Miatas—haven't been like that. Those cars are about a series of carefully designed systems working together to deliver an experience that not everybody is going to like, but is nonetheless joyful to those who "get it." 

But PHEV performance cars have all the potential in the world to be the machines for people who "get it" as well. How can a vehicle with two distinct drivetrains, working harmoniously in concert, not be all about nuance and engineering excellence and the sorts of things that enthusiasts never get tired of talking about? It’s well established that most of the purely combustion-powered enthusiast cars we have now just aren’t what they used to be. Why are we still waiting for those cars to get better? As strange as it looks and as expensive as it’s going to be, the XM is a worthy part of the next chapter, and it makes BMW’s current crop of M cars seem last-generation.

Plainly put, the XM isn’t what it appears to be. Yes, it’s going to be revealed to a cacophony of criticism about its weight, cost, and looks, but do me a favor and think about what it really means. It’s a new beginning, a statement of intent. BMW is not going to slap its full-fledged M badge on just any EV just because they’re pressed in our faces as the future we all must accept. Enthusiast cars, as we all know, are all about nuance. And as strange as it might seem, the XM is, too.

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