BMW XM vs Bentley Flying Spur

What's the difference?

It’s pretty obvious the XM is designed to impress people with big wallets and an appetite for a techy experience that’s also not without a few green credentials. The ability to motor around as a fully-electric vehicle for up to 80km or so is a big plus and the electric-ballroom interior vibe is hard to ignore, as well.

But from our perspective, the full-fat, twin-turbo V8, while offering startling performance, is perhaps a lost opportunity to follow some of BMW’s competitors into the engine-downsizing space. Then again, when you floor the throttle and 2700kg hurtles forward like a big dog on a short chain, you can see where BMW is coming from.

Perhaps the biggest letdown is the ride quality – or lack of it. While it’s understandable BMW wanted the most dynamic version of the XM it could manage, the end result plays against the vehicle’s otherwise long suit of hyper-luxury. Doubtless, BMW would argue that to soften the chassis would have been to introduce a chink into a no-compromise product. But, perhaps, sometimes a sensible compromise is the way forward.

The Bentley Flying Spur Speed is a whole lot of car, for a whole lot of money. Sure, I’d rather have a Ferrari or a Porsche with similar power (and the Panamera shares the same V8 and hybrid set up), but then if you’re in the market for a Bentley like this you already have a garage full of other options. And I can see why you’d add one of these to your collection. Because you can.

Note: CarsGuide attended this event as a guest of the manufacturer, with travel, accommodation and meals provided.

There’s nothing subtle about the way the XM looks. It probably pulls up just short of brutalist (or maybe not) but even those who find its slabs and angles attractive have to admit that it’s bold.

The now-trademark giant nostrils set the mood and the rest of the exterior suggests some kind of armoured transport for presidents rather than wheels for the school run. Doubtless, this will hardly be seen as a fault by those in the market for such a thing.

The real surprise here is that the XM does not share a bodyshell with any other production BMW. Sure, the V8 petrol engine and wheelbase are common to other BMW and M models, but the sheet metal is the XM’s and the XM’s alone. That in itself, is quite a statement of intent.

Bentley seems to have spent the design budget on the Continental GT Speed, which was launched at the same time and gets the same new engine under its slightly sexier bonnet. The big move there has been going from Bentley’s traditional four headlight face to a smoother more modern one with just two lights, or eyes.

The Flying Spur, by comparison, sticks with the more traditional look, and four eyes, but that doesn’t necessarily mean it looks nerdier. Indeed, it’s still an impressive and handsome beast and does a mighty fine job of making this much metal and mass look bold and desirable. 

Truly, vehicles this large tend to look lumpen and making one look as good this Flying Spur Speed does is an impressive feat. Look at the photos and be impressed.

The interior fit out and fittings are stunning, with Bentley boldly claiming it makes the best car cabins in the world. It’s not an outrageous claim, either.

Given the vast exterior dimensions and a weighbridge ticket the wrong side of 2700kg, it may come as a surprise to learn that the XM is strictly a five-seater with not even an optional third row.

That said, the uber-SUV Lexus LX in flagship, Ultra Luxury, trim offers just four seats in deference to the VIP clientele it’s pitched at, but also comes complete with reclining rear seats and a passenger’s side footrest which the XM can’t match.

Staying in the rear seat, there’s lots of legroom and plenty of space under the front chairs for feet. A lot of that is down to the wheelbase the XM shares with the BMW X7, and even behind a tall driver, there’s lots of space. In fact, compared with a BMW X5, there’s a full 150mm of extra legroom.

The pew itself flows into the door trims for a lounge effect which looks great with the contrasting light-coloured trim, and the centre arm-rest folds down to reveal a pair of cupholders. Extra storage space can be found in fold-out pockets in the rear of each front seat which also house a small, lidded panel that opens to reveal USB ports and power sockets. Dual-zone climate controls are also part of the rear-seat experience.

The gee-whizz stuff hasn’t been ignored, either, and the prismatic roof lining is nothing if not a talking point. But would a panoramic sunroof have been of more value to many buyers? The ambient lighting is a nice touch, too.

Up front, the view is dominated by the giant, twin curved animated dashboards. They deliver information and lots of it, to the point where it can almost seem a bit overwhelming.

The head-up display helps simplify things, but there’s absolutely no doubt there’s a lot going on in this cabin. Again, this is modern luxury motoring, but it remains that the menu system will take time to learn, even if the touchscreen function gives you an option on how you control things.

Multi-adjustable front seats are part of the deal and there’s an M-spec steering wheel which is heated. And although it features plenty of buttons, isn’t as daunting perhaps as the multi-spoked equivalent in some high-end AMGs of late.

The stereo system is also worthy of a mention, being a Bowers & Wilkins unit with roof mounted speakers and no less than 1500 watts of power. Digital radio is part of the package.

Even though it doesn’t offer a seven-seat option, luggage space in the rear of the XM is hardly class-leading. Cargo volume with rear seat up is 527L and 1820L with it folded.

Much of the wheelbase is devoted to rear-seat stretching room and although the batteries for the electric motor are positioned under the rear seat, the floor of the cargo area seems quite high.

I’m not going to pretend that I had my laptop out taking notes while we were hitting 200km/h down the back straight at Magarigawa, but at more sane speeds there’s no doubt the rear seats of this car would be a very relaxing, plush, cosseting and pleasant smelling place to sit and work.

That’s at least partly what the Flying Spur Speed is for, a limousine for those who don’t like, or perhaps can’t quite afford, a Rolls-Royce, but still want great British solidity, class and that sense of obscene wealth, probably inherited.

The bonus of the Flying Spur is that it’s also a lovely place to be should you choose either of the front seats, with hugely comfortable seats that are more like couches, endless adjustability and many soothing massage settings for your heated and ventilated pews.

The spinning central 12.3-inch display remains the highlight, offering you a modern touch screen, which can disappear to reveal either three classic analogue dials or a plan piece of dashboard, if you prefer a “digital detox”.

Is “value” even a word that people use when they can afford to shop for a Bentley that costs $581,900, and will not be their only car? At very least, it’s a term that means something different to the people who breathe that kind of rarefied air.

The kind who have memberships to the exclusive Magarigawa Club where the Flying Spur Speed was launched. When just being a member costs a rumoured $1 million a year (and there’s a waiting list to get in), then half that much for a car probably isn’t so much.

The Flying Spur Speed comes with everything you would expect from a Bentley, incredible levels of comfort, a modern hybrid system that allows you to pretend you’re an eco-warrior while driving through the zero-emission zones of big cities like London and plenty of space and shiny things to look at.

The stereo is a Naim for Bentley audio system "arguably the finest in-car hi-fi available in any production car", while you also score a panoramic sunroof and mood lighting and even lovely deep-pile mats in the footwells. Ahh.

Sure, you could buy Ferraris and Lamborghinis for that kind of money, but they don’t have comfortable back seats like this Bentley, for those days when you really need to get to the chopper (parked on your personal helipad) in a hurry.

Here’s where the XM starts to justify its price-tag. While the use of an electric motor to boost a petrol engine has allowed some manufacturers to reduce the capacity of the latter, no such restraint has been shown for the XM. Instead, it gets the full 4.4-litre, twice turbocharged V8 that we’ve come to know and love from this brand.

It’s not that this is the engine’s first date with hybrid technology, but the mild hybrids that have come before it can’t match the XM for sheer brutality when both power units are unleashed.

The petrol V8 can muster up 360kW and 650Nm which, when boosted by the electric motor, jumps to a total of 480kW (combined) and 800Nm.

While the petrol engine drives through an eight-speed torque-converter automatic, the electric motor also drives through the transmission, an arrangement that is a bit different to some hybrids which use the petrol engine for the rear axle and the electric motor to drive the front wheels.

Of course, the requirement for the XM to feature permanent all-wheel drive, regardless of what power unit is running at the time, forces this layout.

Speaking of all-wheel drive, The XM’s version of BMW’s 'xDrive' layout has been specifically tuned for this vehicle and includes torque vectoring as well as a limited-slip rear differential.

The system has the ability to vary the torque split front to rear, with the default rear-bias giving a more sporting feel on good surfaces. An active rear differential also helps give the car a rear-drive feel.

As well as modes for 'Hybrid', 'Electric' and 'eControl' modes, the XM sticks with the M tradition of offering two M buttons which can be configured to set the parameters for steering, driveline, chassis and, in the case of the hybrid XM, the degree of braking regeneration offered.

Four-wheel steering is also part of the XM’s repertoire and, interestingly, there’s no air suspension here; just conventional steel springs.

But it does feature an electrically-adjusted anti-roll bar system which aims to strike a happy medium between what the driver wants and the road conditions demand.

If you’re going to put the word “Speed” in the title of your car, you really can’t mess about when it comes to the powerplant, and Bentley also has a proud history of making hugely powerful V12 engines to live up to. That’s a history that has now ended, with the announcement that the new 4.0-litre twin-turbo V8 in this Flying Spur Speed will be the one and only in all Bentleys, henceforth, including the Continental and the Bentayga SUV.

Bentley’s W12 engine is, sadly, no more, which might well make some older Flying Spurs quite collectable.

The V8 will come in different flavours, of course, and it’s also a hybrid, as is the modern way. Bentley calls the 140kW electric motor attached to the engine an “e-machine”.

Using that machine, the Speed can whisk you around in silent, EV-only mode for up to 81km. With such a stupendous sounding V8 on offer, it’s hard to see why you’d bother, but it’s an option, and the hybrid system is cleverly set up so that the harder you drive, the quicker the battery recharges, so effectively you’d almost never have to actually plug this PHEV in.

With the engine and e-machine combined, you’re looking at a staggering 575kW and 1000Nm, enough to propel all 2646kg of this Flying Spur Speed to 100km/h in just 3.5 seconds.

It might not sound quite as orchestrally moving as the big, sassy W12, but it’s still a hell of a replacement, as it is, in fact, “the most powerful Bentley engine ever”. That will do nicely.

A 25.7kWh lithium-ion battery provides the power for the electric drive. It’s mounted under the rear seat and can produce a purely electric range of between 82 and 88km (based on WLPT test protocols).

Charge time from a conventional wall-box is said to be about four hours but, interestingly, the XM has no provision for DC fast-charging.

Fuel consumption (combined cycle) is an EV-typical 2.7 litres per 100km, which equates to a low 61g/km of CO2.

Once you’ve depleted the battery on a highway journey, expect the petrol V8 to consumer somewhere between eight and nine litres per 100km at cruising speed.

Using EV mode means zero-emission operation but, as with any electric car, how the power is generated to recharge it determines its real-world green-ness.

So, if you were very careful to use your 81km of EV-only range, as often as possible, and you drove very slowly and treated the accelerator pedal with great care, you might, possibly, achieve the Flying Spur Speed’s claimed fuel-economy of 10.7 litres per 100km. 

That’s the great thing about hybrids like this, they are theoretical fuel misers of the highest order. But if you aren’t careful and you care more about enjoying that twin-turbo V8 engine you’ve paid so much money for, you’re never, ever going to get it under 15L/100km, and you’ll quite likely exceed 20L/100km, as we did, with ease, by driving it around a track all day.

Theoretically, again, this Bentley will emit just 33 grams of CO2 per kilometre. 

While any M car is supposed to be rapid and dynamic, it’s also true that the over-arching perception of big SUVs is that they’re comfortable and plush. None of which explains the ride in the XM.

Regardless of how you fiddle with the settings, the ride is always brittle. Those big tyres with their minimal sidewall somehow manage to find every crack and join in the road, and it’s these sharp-edged imperfections that thump through to the cabin the most vocally.

It’s enough to make you wonder who this car is going to appeal to. Will it take to race tracks? Almost certainly not. So the whole point of these suspension settings might be a bit lost on some people.

Performance, meanwhile, is insanely rapid for something that could pass as a bulk carrier. The biggest giveaway to the mass is the transmission’s earnest attempts to keep everything moving by feeling a bit hyperactive on downshifts.

Using the ratios is always going to be the strategy, but with all that torque, maybe it’d be nice sometimes for the trans to hang on to a taller gear and let the boost blow it towards the next corner.

The sound track? Polarising. Even if it doesn’t convince you that Hans Zimmer (who developed the various electronically-synthesised noises the XM makes) should stick to winning Oscars, the augmented sounds are background noise rather than the main event here.

Even the petrol V8’s naturally stirring backing vocals have been electronically tweaked with debatable results.

That said, it’s nice to have something to listen to that isn’t the insistent tyre roar which becomes even louder on coarse-chip surfaces.

Steering effort is light but there’s not a lot of feedback in terms of actual feel. In fact, it’s borderline detached and only the sheer speed of the rack confers any athleticism.

Also, the rear steering seems to come in a few milli-seconds after the front has started to turn. And for all that all-wheel-steering agility, this is never a car that shrinks around you.

Any car with a whopping 575kW and 1000Nm is going to be interesting, even invigorating to drive, but you’d have to say the smaller and lighter it is, the more excitement, and even fear, you’re going to be faced with.

In the case of the Bentley Flying Spur Speed, you’re talking about an enormous, and enormously luxurious and comfortable, sedan that’s designed to carry more than two people, and weighs a hefty 2646kg.

It’s a limousine powered by a rocket, as I said earlier, but looking at the size, and pondering the weight of it, you really don’t expect too much in the way of thrills. Effortless performance, sure, titanic overtaking thrust, perhaps, but then you read the fine print and note that this Flying Spur Speed can hit 100km/h in 3.5 seconds.

That’s seriously fast in anything, but in a car this big, and filled with as much luxury as a mid-sized super yacht, it feels other worldly. 

Hammering the big Speed around a tight, intense race track feels strange at first and then strangely comfortable. Even sitting in the back wasn’t so much frightening as amusing, as the big Bentley simply slopes through any challenge you throw at it.

Sure, I’d like it to be louder, and you do miss the sound of the old 12-cylinder engine (and Bentley fans in particularly might find its absence upsetting), but the V8 is still throaty enough to please your ears, and it’s important to consider that it’s actually more powerful than the old W12, which is no mean feat.

Compared to the shorter, sharper Continental GT Speed we drove on the same day, the Flying Spur does have a bit more body roll, a bit more pitch and dive under braking from 200km/h, or when accelerating ballistically out of slow corners, but it’s still stupendously impressive for what it is.

And that is a luxury limousine that can turn itself into a race track weapon if you, and your three passengers, want it to. 

The Flying Spur Speed comes with 10 airbags and it has not been crash tested. Bentley also has its own 'Safeguard' suite of technologies including auto emergency braking, 'Swerve Assist' and 'Turn Assist'. 

Other tech includes 'Predictive Adaptive Cruise Assist with Lane Guidance', lane departure warning, emergency assist, remote park assist and 3D surround-view monitor.

Like a lot of manufacturers, BMW knows consumers can be leery of EV tech when it comes to the cost of battery replacement. So, as well as the five-year/unlimited-kilometre warranty on the whole vehicle, there’s also eight years or 160,000km of cover for the high-voltage battery.

Servicing intervals are based on how the car has been used and it will inform the owner when a service is required.

A servicing package is included in the purchase price and BMW even throws in three years of roadside assistance.

The Bentley Continental GT Speed comes with a five-year, all-inclusive servicing plan as standard.

That sounds good, but stunningly, Bentley still only offers a three-year manufacturer warranty, albeit one with no mileage limitations. That's way below industry standard these days.

The battery that forms part of the hybrid system is, however, warrantied for eight years, or 160,000km.