BMW M8 vs BMW XM

What's the difference?

With dramatic looks, a luxurious spec, and impeccable quality, the BMW M8 Competition Gran Coupe remains supremely well controlled as it delivers eye-widening performance and amazing dynamics. But there’s an ‘edge’ to the experience you need to be ready for. If I was determined to head for the Aussie ‘fast lane’ in a BMW 8 Series Gran Coupe I’d opt for the M850i and pocket a lazy $71K (enough for a cheeky M235i Gran Coupe to add to your collection).

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.

Want to start a vigorous car enthusiast discussion (more a verbal punch-up)? Simply ask whether a four-door car can be a coupe.

Traditionally, the answer is no, but over time numerous automotive brands have applied that description to cars with more than two doors, including SUVs!

So, here we are. A four-door ‘Gran Coupe’, and the M8 Competition version retains the smoothly tapering turret and frameless side glass that help give selected BMW four-door models the same swoopy, coupe look.

At close to 4.9m long, a fraction over 1.9m wide, and under 1.4m high, the BMW 8 Series Gran Coupe has a firmly planted, low-slung, wide-track stance. Always a subjective call, but I for one, think it looks stunning, especially in our test car’s ‘Frozen Brilliant White’ matt paint finish.

In an era of comically oversized BMW grilles, things are relatively under control here, with a bright black finish applied to that ‘kidney grille’, as well as the huge front bumper air intakes, front splitter, front fender vents, exterior mirrors, window surrounds, 20-inch rims, lip spoiler on the boot, rear valance panel (incorporating a functional diffuser), and quad exhaust tips. The roof’s black, too, but that’s because it’s made of carbon-fibre.

Overall the M8 Competition Gran Coupe is a compelling combination of strong, confident character lines along the bonnet and lower flanks, with tightly wrapped curves following the high hip line, and more organically irregular, yet distinctly BMW shapes in the head- and tail-lights. 

The interior is a beautifully balanced design with a broad centre console sweeping up to the middle of the dash and wrapping around to focus on the driver, in typical BMW fashion.

 The multi-adjustable sports front seats are immaculate, with high-end quilting in the centre section matching a similar treatment in the doors. The dark grey (full) leather trim is offset by carbon and brushed metal trim elements for a cool, calm and focused feel.

Crack the bonnet open and a spectacular ‘BMW M Power’ carbon cover dressing the top of the engine is guaranteed to impress friends and family.

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.

Of the M8 Competition Gran Coupe’s 4867mm overall length, 2827 of it sits between the front and rear axles, which is a pretty healthy wheelbase for a car this size (and 200mm more than the 8 Series two-door coupe).

Space up front is generous, and one upside of a four-door, rather than two-door coupe, is you’re not struggling quite so much for space to get in and out when parked next to other cars.

Once inside, there’s plenty of storage up front, with a large lidded box/armrest between the front seats, twin cupholders in the centre console, as well as another covered area for wireless phone charging and extra bits and pieces in front of that. Long door pockets provide space for bottles, and the glove box is a decent size. There’s 12V power as well as USB sockets for media connection, with charging outlets in support.

At first glance you’d swear the rear seat was designed as a two-seater only, but when push (literally) comes to shove a centre passenger can squeeze in, legs straddling the rear console.

In terms of legroom, at 183cm (6’0”) I could sit behind the driver’s seat set for my position with knee room to spare, but headroom is another matter, with my noggin making solid contact with the soft Alcantara headlining. It’s the price you pay for this car’s racy profile.

There’s a neatly trimmed storage box and two cupholders in the fold-down centre armrest, plus door pockets with enough room for small bottles. The rear console houses dual climate controls, twin USB power sockets, and a small oddments tray, as well as buttons for the optional rear seat heating fitted to our test car ($900).

The 440-litre boot is a bit like the car itself - long and wide, but not very high. The rear seat split-folds 40/20/40 if you need more space, and the boot lid is automatic with a hands free function. But don’t bother looking for a spare of any description, a tyre repair kit is your only option.

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.

The XM is one of those 'no options' vehicles. That is, you pay the basic price, you get one with the lot. The aged leather and even the optional 23-inch wheels and tyres are no-cost options, so it’s clear where BMW is aiming the thing.

As well as the plug-in driveline, all-wheel drive and all the M driving focus, the XM features plenty of tech including massaging front seats, heated seats all around, a high-end stereo, heated and cooled cupholders, four-zone climate-control, wireless phone charging and twin, curved info screens for the driver measuring 12.3 and 14.9 inches. The novel roof lining also features 100 pin-point LEDs for effect.

The cost of such detailing is a not insubstantial $302,200. That figure does, however, undercut two of its main rivals, the Lamborghini Urus ($395,888) and the Aston Martin DBX ($356,512).

It’s also worth mentioning that the XM is not even BMW Australia’s most expensive model; in fact, it’s fourth on the ladder.

The M8 Competition is powered by an all-alloy, 4.4-litre twin-turbo V8 engine, featuring direct-injection, as well as the latest version of BMW’s ‘Valvetronic’ variable valve timing and ‘Double-VANOS’ variable camshaft control, to produce 460kW (625hp) at 6000rpm, and 750Nm from 1800-5800rpm.

Designated ‘S63’, the engine’s two twin-scroll turbos are located, along with a cross-bank exhaust manifold, in the engine’s (90-degree) ‘hot vee.’ 

The idea is consistent transmission of exhaust energy to the turbos for improved response, with the reversal of usual practice completed by inlet manifolds positioned on the engine’s outer edges.

Drive goes to all four wheels via an eight-speed ‘M Steptronic’ (torque converter) auto transmission with ‘Drivelogic’, and dedicated oil cooling, as well as BMW’s ‘xDrive’ all-wheel drive system.

The xDrive set-up is built around a central transfer case housing an electronically-controlled, variable multi-plate clutch, with front to rear drive distribution set to a default 40:60 split.

The system monitors multiple inputs including, wheel speed (and slip), acceleration and steering angle, and is able to vary the ratio up to 100 per cent rear thanks to the ‘Active M Differential.’ 

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.

Claimed fuel economy for the combined (ADR 81/02 - urban, extra-urban) cycle is 10.4L/100km, the M8 Competition emitting 239g/km of CO2 in the process.

Despite the standard auto stop/start function, over a week-long combination of city, suburban, and freeway running we recorded a (dash-indicated) average of 15.6L/100km.

Pretty thirsty, but not outrageous when you consider this car’s performance potential, and the fact that (purely for research purposes) we exploited it regularly.

Recommended fuel is 98 RON premium unleaded, and you’ll need 68 litres of it to fill the tank. That equates to a range of 654km in line with the factory claim, and 436km using our real-world number as a guide.

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.

There’s something teutonically symmetrical about the way the M8 Competition Gran Coupe delivers its prodigious thrust.

Peak torque of no less than 750Nm is available from just 1800rpm, remaining on full song across a broad plateau all the way to 5800rpm. Just 200revs later (6000rpm) peak power of 460kW (625hp!) takes over to finish the job, with the rev ceiling sitting just over 7000rpm.

That’s enough to slingshot this 1885kg bruiser from 0-100km/h in 3.2 seconds, which is supercar fast. And the engine and exhaust noise produced by the 4.4-litre twin-turbo V8 during such rapid acceleration is suitably brutal, courtesy of electronically-controlled flaps in the system opening up. 

On a more civilised drive you can reduce the exhaust noise via an ‘M Sound Control’ button on the centre console.

The eight-speed auto is fast and positive, especially in manual mode, which dials up the fun via wheel-mounted paddles. And when it’s time to direct this car’s forward momentum into lateral movement BMW has brought in the engineering heavy artillery.

Despite its frameless door body structure the M8 Competition Gran Coupe feels solid as a rock thanks in no small part to its ‘Carbon Core’ construction, using four primary components - carbon-fibre-reinforced plastic (CFRP), aluminum, high-strength steel, and magnesium.

Then the ‘Adaptive M Suspension Professional’ (with active anti-roll stabilisation), the tricky xDrive continuously variable AWD system, and active M Sport diff combine to keep everything under control.

Suspension is a double wishbone front, five-link rear arrangement, with all key components in alloy to minimise unsprung weight. In concert with the electronic wizardry on-board, it helps keep the M8 buttoned down with only modest body roll in enthusiastic cornering, as the rear-biased AWD system seamlessly distributes drive to the axle and wheels that can make best use of it.

The price you’ll pay for the track-ready tune is in compromised ride comfort. Even in the ‘Comfort’ setting, the M8 Competition is firm, and feels corrugations and imperfections to a surprising degree.

An alignment of the BMW 8 Series planets left me with the keys to this car and the M850i Gran Coupe (also using the Carbon Core body) at the same time, and the difference between their softest settings is appreciable.

Also be aware that at 12.2m the M8 Gran Coupe’s turning circle is substantial, and it’s just as well all that camera, sensor and self-parking tech is available to help you guide this ship into port.

The M8’s electrically-assisted, variable-ratio steering features an ‘M’ specific calibration to deliver satisfying precision and good road feel. But in similar fashion to the ride a noticeable amount of unwelcome feedback comes through to the wheel.

The fat Pirelli P Zero rubber (275/35 fr / 285/35 rr) grips hard, and the monster brakes (ventilated all around, with 395mm rotors and six-piston calipers up front) wash off speed without fuss or fade.

But overall, you’ll have to live with a less refined drive when you sign on for the M8 Competition. Straight away it feels faster but lacks the M850i’s lighter touch. No matter which drive or suspension mode you select, responses are more aggressive and physical.

To fully explore and enjoy the M8 Competition’s abilities it feels like the race circuit is its most appropriate habitat. On the open road, the M850i is all the Gran Coupe you’re going to need.

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.

As well as the usual passive safety features, the XM also hides the latest active safety gear. In fact, BMW reckons the XM has more driver assistance than any other M car before it.

Those elements start with the 'Driver Assistant Professional' which bundles active cruise-control with stop-go ability, steering and lane-keeping control, automatic speed limit assist and active navigation.

Parking assistance is also featured which incorporates a reversing assistance function, front, rear and panoramic camera views with a 3D view built in.

BMW’s 'ConnectedDrive' includes an emergency call function in the event of a crash or other emergency.

No ANCAP assessment so far.

BMW offers a three year/unlimited km warranty, which is at least a couple of years off the mainstream market pace, and lagging other premium players like Mercedes-Benz and Genesis, both sitting at five years/unlimited km.

Roadside assistance is included for the duration of the warranty period, and the standard ‘Concierge Service’ provides everything from flight information, to global weather updates, and restaurant recommendations, from a real human.

Technically, service is ‘condition based’ with the car telling you when it’s time to hit the workshop, but you can use every 12 months/15,000km as a guide.

BMW Australia offers ‘Service Inclusive’ packages that require customers to pre-pay for servicing, allowing the cost to be covered off in finance or leasing packages and reducing the need for concern about paying for maintenance further down the track.

BMW says there are different packages available, from three to 10 years, or between 40,000 and 200,000km.

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.