BMW XM review – the most powerful BMW on sale, and also the worst

There’s no doubt the BMW XM is one of Munich’s most controversial models of all-time, but it was built on a solid business case. Luxury performance SUVs like the Porsche Cayenne and Lamborghini Urus are lucrative to say the least, and for BMW to make inroads into that market is a logical move. A regular-brand BMW such as an X7 perhaps doesn’t quite have the cachet to entice the most image-conscious of buyers, and so badging this car as a bespoke M product makes sense. Adding to the prestige factor, it’s the most powerful M production car yet.

So while it might be unpalatable to some that the first bespoke M model since the ’70s M1 is a plug-in hybrid SUV, it’s a pragmatic product. What we must do, then, is judge the XM as both an SUV and as an M car, but it seems even BMW is struggling to know what this car really is. In the UK it’s now available not just as a flagship V8 hybrid monster, but also a hybrid six-cylinder model with less performance than the smaller X3 M50. 

> BMW X3 M50 review – 393bhp six-cylinder SUV previews the X3 M

Engine, gearbox and technical highlights

Performance-wise, the XM packs some big numbers. In range-topping 'Label' spec the engine is a 4.4-litre twin-turbocharged V8, with an electric motor packaged together with the eight-speed ZF transmission. That V8 generates plenty on its own but with the electric drive system lending a hand, total power and torque outputs are 738bhp and 738lb ft to make it the most powerful M car ever sold. Weight distribution in the XM is symmetrical too, close to 50:50 front to rear.

The electric motor is the latest generation of BMW's eDrive units with nearly 200bhp and more than 300lb ft of torque, which easily moves the XM’s bulk around when it’s in EV mode. The gigantic battery pack gives the XM decent pure electric range, with 55 miles from a full charge and up to 87mph before the V8 kicks in. 

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The ‘entry-level’ XM 50e combines a 3-litre twin-turbocharged B58 straight-six with plug-in hybrid electrical assistance. The result is a total output of 463bhp and 513lb ft, a whole 275bhp less than the range-topper and a number that drags the XM well down into M-lite territory, especially when you consider its weight. The 0-62mph sprint comes in 5.1sec before a 155mph top speed, putting it five tenths behind the less powerful, much less expensive X3 M50.

A long e-range was a target from the beginning, M head of engineering Dirk Hacker tells evo: ‘From my point of view, if you go with a hybrid car you need a real, usable electric range – a minimum electric range for a real offer.’ In our testing the XM retained full EV functionality for long periods even without plugging in to charge, making it a useful hybrid system. We also saw an average of around 30mpg in the 50e, which seems relatively economical given its size and weight.

Performance, ride and handling

The XM's spacious cabin is a comfortable place, until you reach any bumpy or uneven bits of road. The steel springs and adaptive dampers give a ride that’s firm with a capital ‘F’ (and maybe a second F thrown in for good measure). Wheel size starts at 21 inches, with our test car wearing 22s; 23s are an option. Despite standard-fit electronically controlled dampers for the double-wishbone front, multi-link rear suspension, it’s simply too stiff. Even in less focused 50e-form, the chassis squirms and fidgets like you’re driving on cobbles at low speed, with a highly uncomfortable bassy resonance filling the cabin in the process – the ride is so brittle I actually had to check our test car wasn’t still riding on its shipping blocks…

It’s quick in V8-form, as you’d expect, but with 2.7 tonnes to haul around, it doesn't feel as eye-wideningly rapid as the power and torque figures might suggest. The same applies to the XM 50e, with its modest output giving it a power-to-weight ratio in-line with a hot supermini like the £26k Hyundai i20 N. It feels that way too, as while the instantaneous electric torque gives you a kick from standstill, that soon tails off to pace you’d usually associate with a non-M product. It doesn’t feel slow in isolation and you can make swift progress, but given BMW markets the XM as a ground-up bespoke M car you’d certainly expect more. The gearbox blends into the background well in normal driving, but it doesn’t provide any sort of feedback if you decide to increase the pace, making changing gears with the paddles a little pointless.

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Nor, as the kerbweight suggests, does it feel terribly agile. Hit a bump at medium speed and the body keeps moving for some time afterwards before settling; ask a high-speed direction change of the XM and it feels clumsy. To their credit, the 48V active anti-roll bars do their job very well in most circumstances, keeping the big body spookily flat as we descend down a switchbacking series of canyon roads. Standard-fit rear-wheel steering, the first on an M car, does help here too. It’s so subtle in its operation that you don’t necessarily feel what it’s up to as it virtually shortens the 3.1m wheelbase, or lengthens it at high speeds. 

The XM’s XXL wheelbase (longer than an entire Toyota iQ) helps on the motorway too, where directional stability in fast curves is impressive. Dynamically, however, the XM feels a curious mix overall: the active anti-roll software helps the XM corner with a commendably flat stance, yet the body can be upset by bumps and continue a lateral or diagonal motion after the bump has passed. Yet at high speeds, big bumps are absorbed beautifully and longitudinal stability at autobahn speeds is stellar. And on the flipside, ride quality over minor bumps and surface imperfections at lower speeds is irritatingly fractious – no doubt largely due to the penny farthing-spec wheel diameters.

Subjectively, the BMW X6M is a more enjoyable driving experience for around £20k less than the XM’s circa £150k starting price; Aston Martin’s DBX, Bentley’s Bentayga and Lamborghini’s Urus are more expensive still, but they’re also more rewarding to drive. If you’re looking for a new BMW with quirky interior design, strong performance and practical family credentials, the X3 M50 provides all of that for £60k less. The XM might stack up as a business case, but as a genuine M product, there’s little to enjoy here. 

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Interior and tech

The XM’s interior design is just as bold and divisive as the exterior, with a blocky, plain aesthetic that sets it apart from most of the range. Most of the switchgear and controls are carried across from elsewhere in the lineup but this does feel like a unique product, with a huge illuminated, textured panoramic sunroof blind the centrepiece of it all and a strong talking point for passengers. Activating sport mode at night for the first time can be a little jarring as the entire cabin shifts to a bright, blue and red theme, roof included. 

Climb in the front and it feels curiously cramped: a lot of dashboard, not a lot of knee room. The seats feel a touch too high, even in their lowest setting. It’s the opposite in the back: the XM’s interior concept is a driver-focused front cabin and luxurious ‘M Lounge’ rear, with a striking three-dimensional roof lining, epic legroom and decadently comfortable wraparound-cushioned rear seating.

Go to put your bags in the back and there’s a big boot with a flat floor and a flush load lip, but it’s very high, because of the Rubik’s Cube packaging requirements of an enormous battery pack and fuel tank. That also means there’s nowhere to stash the charging cable, so each XM comes with an overnight bag-style holdall in the boot to put it in.

This car might have some strong high-speed cruising abilities, but road noise makes this a less enjoyable experience on the UK’s mottled roads. Whether at low, urban speeds or on the motorway there’s a persistent booming throughout the cabin, almost as if you’ve left a window cracked for that horrible overpressure feel. Another niggle is that the rear tint in our test car is the darkest I’ve encountered, so much so that you can’t see much at all through the rear window – the huge dimensions at play make that slightly disconcerting when parking or driving at night. 

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Price, specs and rivals

The current BMW XM lineup consists of just two models in the UK, starting with the six-cylinder 50e at £112,820 before jumping right up to the 738bhp XM Label at £154,800. Tick enough options and you’ll see much higher figures than these, with our 50e test car coming with options such as the £4400 uprated sound system to make it a near-£120,000 car.

A premium BMW SUV with acres of space and a more polished driving experience is the X7, starting from £118k, but if you're looking for performance the V8-powered X6 M has it in abundance for just shy of £140k. Look elsewhere in the market and the Mercedes-Benz GLS is a good alternative at a £110,800 starting price, rising to £158,400 for the V8-powered 63 model with over 600bhp. The Audi SQ7 is a little more ordinary and doesn't have quite the same performance to offer, but it’s a much more polished product than the XM and for a much more attractive £100,120 price tag.

BMW XM specs

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