Mercedes-Benz GLS vs Bentley Flying Spur

What's the difference?

The GLS63 is an intimidating beast from afar, but it rewards its occupants in almost every way. Yep, there really isn’t a box it doesn’t tick without serious compromise, such is its breadth of capability.

If there was ever a Swiss Army Knife of cars, the GLS63 is definitely a contender for the title, one that makes it very hard to wipe the smile off your face. Just make sure you can fit it in your garage first…

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.

If the GLS63 was a Marvel superhero, it would undoubtedly be the Hulk. Simply put, it has road presence like few others. In fact, it’s frankly menacing.

Of course, the GLS is already pretty intimidating due to its sheer size and blocky design, but the GLS63’s full-fat AMG treatment takes it to another level.

Naturally, the GLS63 gets an aggressive body kit, with its purposeful bumpers, side skirts and rear spoiler serving as instant reminders of what you’re dealing with, but it’s AMG’s signature Panamericana grille insert that really hammers home the point.

Around the side, the GLS63’s 22-inch alloy wheels with staggered tyres (front: 275/50, rear: 315/45) make their presence known, positioned below the wheelarch extensions.

That said, some fun’s also had at the rear end, where the GLS63’s diffuser element integrates the foreboding sports exhaust system with quad tailpipes very neatly.

The focused Multibeam LED headlights also look the part, while the opposing LED tail-lights tie everything together outside quite nicely.

Inside, the GLS63 stands out from the GLS crowd with its sports steering wheel with Dinamica microfibre accents, and multi-contour front seats, which are covered in Nappa leather alongside the armrests, dashboard and door shoulders and inserts.

Of note, the doors bins are unfortunately of the hard plastic variety, which is very disappointing in a vehicle that costs this much. You would expect that cow hide would also been applied to them, but alas it isn’t.

The GLS63’s black headliner serves as an obligatory reminder of its sporting intent, and while it makes for a dark cabin, metallic accents are prominent throughout, while the optional trim (our test vehicle had carbon-fibre) mixes things up, alongside the ambient lighting.

And let’s not forget the GLS63 is still loaded with plenty of cutting-edge technology, including a pair of 12.3-inch displays, with one the central touchscreen and the other the digital instrument cluster.

Both are powered by Mercedes’ class-leading MBUX multimedia system and feature Apple CarPlay and Android Auto support. This set-up arguably remains the best there is today thanks to its speed and breadth of functionality and input methods.

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.

Measuring 5243mm, 2030mm wide and 1782mm tall with a 3135mm wheelbase, the GLS63 is an upper-large SUV in every sense of the term, which means it’s also very practical.

For example, cargo capacity below the load cover is decent, at 355L, but stow the 50/50 power-split-folding third row via the boot and it’s very good, at 890L, or drop the 40/20/40 power-split-folding middle bench, too, and it becomes a cavernous 2400L.

Better yet, the boot’s aperture is almost square, and its floor’s flat, while there’s no load lip to contend with, making loading bulkier items even easier. Up to four tie-down points are also on hand (depending on seating configuration) to secure loose cargo.

Under the false floor is the space-saver spare, which is to be expected, but what isn’t expected necessarily is the fact there’s also enough room there for the cargo cover when it’s not in use, which would be the case if six or more passengers are regularly onboard.

Moving into the power-sliding second row, the GLS63’s practicality is once again brought to the fore, with up to six-plus inches of legroom available behind my 184cm driving position.

There’s also two inches of headroom with the panoramic sunroof in situ, not to mention just enough toe-room. The GLS63’s small transmission tunnel and sheer width also mean three adults can be seated on the middle bench with few complaints.

Amenities-wise, the second row has map pockets on the front-seat backrest and a small fold-down cubby below the rear climate controls, with it containing two slots for smartphones and a pair of strategically placed USB-C ports.

The rear door bins can take one large bottle each, while a fold-down central armrest is also on hand, featuring a shallow tray and retractable (and flimsy) cupholders.

Alternatively, the $2800 Rear Seat Comfort Package fitted to our test vehicle subs in a tablet that can control the multimedia system, a wireless smartphone charger and a small cubby into the former, as well as a heated/cooled cupholder atop the rear of the centre console.

In the third row, it’s not quite as roomy if you’re an adult. With the middle bench in its most accommodating position, my knees still brush up against its backrest, which is to be expected given it’s primarily designed for children. I also have an inch of headroom there.

Nonetheless, getting in and out of the third row is relatively easy as the power-operated middle bench tumbles forward and provides just enough space to make entry and exit somewhat graceful.

When seated, rear occupants are treated to two USB-C ports and one small cupholder each, so they’re arguably taken better care of than those in the middle.

Child seats are well and truly accommodated, with four ISOFIX and five top-tether anchorage points fitted across the second and third rows, although the latter will inevitably prove to be a much tighter fit.

The driver and front passenger are still taken care of, with a front cubby taken up by two heated/cooled cupholders, a wireless smartphone charger, two USB-C ports and a 12V power outlet, while their door bins take one large and one small bottle each.

In-cabin storage options include the large central storage bin, which hides another USB-C port, while the glovebox is on the smaller side, with about a third of it taken up by the fragrance, which is pumped into the cabin to ensure the interior always smells its best.

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.

The GLS63 is powered by a familiar 4.0-litre twin-turbo V8 petrol engine, with its version producing a thumping 450kW of power at 5750rpm and 850Nm of torque from 2250-5000rpm.

This unit is mated to a nine-speed torque-converter automatic transmission and AMG’s fully variable 4Matic+ all-wheel-drive system with torque vectoring and a rear limited-slip differential.

This set-up also features Mercedes’ EQ Boost 48V mild-hybrid system, which actually gives a 16kW/250Nm electric boost in short bursts, such as when accelerating off the line.

Speaking of which, the GLS63 sprints from a standstill to 100km/h in just 4.2 seconds, while its top speed is electronically limited to 250km/h.
 

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.

The GLS63’s fuel consumption on the combined-cycle test (ADR 81/02) is 13.0L per 100km, while its carbon dioxide emissions are 296 grams per km. All things considered, both claims are unsurprisingly high.

In our real-world testing, we averaged a fearsome 18.5L/100km over 65km of driving, split between highways and country roads, so not your usual mix. A very heavy right foot definitely influenced that result, but don’t expect to do too much better in a normal run.

For reference, the GLS63’s 90L fuel tank can be filled up with 98RON petrol at a minimum.

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. 

Frankly, the GLS63 has absolutely no right being as capable as it is. It’s a really big bus that’s legitimately convinced it’s a sports car half its size.

Being a GLS variant, the GLS63 has independent suspension consisting of four-link front and multi-link rear axles with air springs and adaptive dampers, but its party trick is the addition of active anti-roll bars.

In what feels like magic, the GLS63 is simply not intimidated by corners, despite having massive dimensions and a considerable 2555kg (kerb weight) to deal with.

The active anti-roll bars make the GLS63 so much easier to drive fast through the twisty stuff, almost eliminating body roll, taking one key variable out of the equation for the driver. Active engine mounts are also fitted, helping to settle things even further.

The electric power steering on hand is also good. It is speed-sensitive and has a variable ratio, which basically makes the set-up more direct when it needs to be. It’s typically light in hand, too, until one of the sportier drive modes is engaged and extra heft is added.

So, handling is scarcely believable, which means the ride must be compromised, right? Yes and no. With the adaptive dampers in their softest setting, the GLS63 is very compliant. In fact, we’d say it feels luxurious when compared to other high-performance SUVs.

That said, our test vehicle was fitted with the optional 23-inch alloy wheels ($3900), which look the part but expose sharp edges and other road imperfections, not to mention generate noise easily heard inside. Naturally, feedback is exacerbated in the sportier drive modes.

Anyway, there’s more performance, and the GLS63 has the rest in spades. Its engine is a powerhouse in every sense of the word. It’s so powerful, in fact, that it hilariously hunkers down off the line or when suddenly accelerating at low speed.

Thanks to the mild-hybrid system, wads of torque is available from the get-go, making for a highly responsive driving experience, even in those rare moments when the engine isn’t on song.

While not as characterful as some of the other members in the 63 series, the GLS63 still makes some thoroughly entertaining noises, with its sports exhaust system popping like mad while on the overrun.

All of this ability is very well and good, but you need to be able to pull up quickly, and the high-performance braking package (400mm front and 370mm rear discs with six-piston fixed callipers and single-pot floating stoppers respectively) mercifully does exactly that.

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.

As with all Mercedes-AMG models, the GLS63 comes with a five-year/unlimited-kilometre warranty, which currently sets the standard for the premium market. It also comes with five years of roadside assistance.

The GLS63’s service intervals are relatively long, at every 12 months or 20,000km (whichever comes first). Better yet, it’s available with a five-year/100,000km capped-price servicing plan, but it costs $4450.

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.