Mercedes-Benz SL63 vs Bentley Continental

What's the difference?

The new Mercedes-AMG SL63 4Matic+ is guaranteed to turn heads for decades to come. But there’s enormous design and engineering substance underpinning this car’s undoubted good looks. Stunning performance, superb dynamics and top-shelf safety make this a powerhouse GT to be reckoned with.

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

Any fears Bentley was heading in the wrong direction by abandoning 12 cylinders for hybridisation (not that it had a lot of choice) should be totally salved by the Continental GT Speed. It is a hugely capable, fabulously luxurious and beautiful to behold grand tourer that deserves extra points for not being an SUV. It might just be the supercar you could drive every day, with no complaints.

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

Rather than a strict two-seater, this time around the SL adds the flexibility of ‘+2’ rear seating while the previous 'Vario’ folding hardtop has been binned, the new car returning to a traditional, electrically-folding and weight-saving (-21kg) soft top. 

Mercedes-Benz design chief Gorden Wagener started the new model’s development from a ‘clean sheet’ and Mercedes-AMG says “not a single component comes from the predecessor SL, or any other model such as the AMG GT Roadsters”. 

Always a subjective call, but I think this car’s proportions are just about perfect. The lengthy bonnet with its twin longitudinal ‘Power Domes’, raked windscreen and fat haunches create a wide stance and presence that’s almost impossible to ignore.

Aggression, as with the sinister headlights and 21-inch rims, is subtly combined with soft curves along the flanks and around the rear. Note the seamless door handles.

And it’s not all about aesthetics. Active aero has been integrated into the front apron and retractable rear spoiler. Plus the ‘Z-fold’ roof design does away with the need for a separate cover.

The interior is sub-zero cool with slick screens, an 11.9-inch display covering multimedia and a 12.3-inch unit for instrumentation ahead of the driver, being particular highlights.

Turbine-style air-vents at the leading edge of the split-level dash and alloy trim elements are a tip-of-the-hat to SLs past and the deft mix of large flat surfaces with complex curves oozes design confidence.

I don’t think I’ve ever heard so much interesting waffle about the design of any car, ever, but before we get to the wild, and wildlife, justifications for how it looks, just feast your eyes on it. 

Now, not everyone might love it, but it’s hard to imagine a huge, super coupe looking any better than this thing does. It’s no Ferrari, sure, but realistically it doesn’t have to compete with that, because it’s a cruiser as well as a bruiser, a supercar you can be quiet and comfortable in. A Rolls-Royce with rocket engines, even. 

The most obvious change, of course, is that Bentleys have had four headlights, or four eyes if you like, for so long that seeing this new one with two is a major shock, a big shift, but somehow it works.

The proportions, the elegance, the bold 'be big and bold and give no damns what anyone thinks', it’s just impressive, and the interior reflects that same, luxury ethos.

Apparently the new-look Continental is built on three design principles, the first of which is, amusingly, 'Resting Beast'. This is supposed to reflect how the Bentley looks from side on; like a tiger, stalking its prey, or perhaps resting and thinking about its prey. It’s all muscles and strength and power, but also elegance. And who doesn’t imagine tigers walking red carpets in ball gowns?

Principle two is 'Upright Elegance', and here you’re supposed to see, in the car, the strong vertical line one finds in the chest of a thoroughbred horse when it’s standing in particularly powerful way. Great. Love it.

And finally, there is the 'Endless Bonnet', which is a horizontal line that goes from the front of the car - via the bonnet obviously - and all the way to there rear, via cat-like haunches, providing an impression of “speed, even when standing still”.

Those are the bold strokes, but it’s all the little details that make it sing, like the beautiful jewellery-like look of the headlights, which are meant to resemble a tiger’s eyes. So many cats, is it any wonder I started thinking of the Bentley as a very, very flashy Jaguar?

It’s important to note that while it looks very new - and 68 per cent of the Continental’s parts are new - the body panels are carried over, while the front and rear are all new. This is one very effective mid-life facelift, with a heart transplant, then.

In the context of a high-performance GT, practicality is pretty impressive.

At just over 4.7m long the SL is a sizeable machine and much of its lengthy (2700mm) wheelbase is devoted to making the driver and front passenger comfortable.

There’s plenty of space for that pairing and just enough storage to cope with the ‘things’ they’ll typically bring with them.

Door pockets offer enough room for a few odds and ends, although you’ll struggle with even a medium-size bottle unless you’re willing to lay it down horizontally along the top of the aperture.

A handy lidded bin between the front seats doubles as a centre armrest, there are two cupholders under a sliding lid in the centre console and the glove box is a decent size. 

Power and connectivity options run to four USB-C ports, a 12-volt socket and the wireless device charging pad.

Then there are the rear ‘+2’ seats, and Mercedes makes no bones about the fact they’re intended for occasional use only, even suggesting a 1.5m occupant height limit.

And there’s no doubt they offer a handy emergency seat or a fun kids’ zone. Just ask a Porsche 911 Carrera owner how much this kind of seating arrangement increases a sports car’s flexibility.

At 183cm I gave the back seat a crack, which meant sliding the front (passenger) seat way forward with the backrest close to upright. But I squeezed in, and there was just enough legroom for a person in front at the same time. 

With the roof in place there’s the added pleasure of cranking your head over to around 45 degrees. But it’s do-able! 

No storage, adjustable ventilation, or power back there. But that’s fair enough, especially given there are USBs available in the front centre storage box.

Boot volume is 240 litres with the roof up and 213 litres with it folded, which is enough for some light luggage, and not too shabby when you think a Toyota Corolla hatch offers up just 217 litres (with all seats up).

There’s a 12V socket in there, but don’t bother looking for a spare, in the event of a flat your only option is a repair/inflator kit.

So a two-door, '2+2' grand tourer isn’t entirely built with the term 'practicality' in mind and it could be argued the existence of this Bentley Continental, the fourth generation, is something of a surprise, when you consider most people just buy SUVs and Bentley has done quite well with its Bentayga (which will, in future, share the same engine used here).

But for what it is, a two-seat car with occasional seating in the rear for emergencies, or very small children, it feels entirely fit for purpose.

An actual human can sit in the back, but it does feel a bit claustrophobic, and you’d be so jealous of how comfortable the people are in the front.

The 20-way adjustable front pews feel like grand armchairs for grand touring, fabulously comfortable - although you can slide across them a bit when driving on a race track, not a common problem - and plush to the touch.

They now come with a 'Wellness Facility' that brings postural, massage and climate functions to help with fatigue on long journeys - and epic blasts across multiple European countries is clearly what this thing is designed for.

In general, the cabin is just lovely, Bentley claims it does the best car interiors in the world and while Rolls might argue, it’s a pretty fair statement.

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

As always, value becomes a nebulous term once the price of a car surges into the multiple hundreds of thousands. The Bentley Continental GT Speed will set Australian buyers back a whopping $581,900, before on-road costs.

Yes, you really can buy Ferraris and Lamborghinis for that kind of money, but Bentley assures us its buyers have already owned such fearsome machines, grown tired of their compromises and want something that’s just as fast, but 1000 times more comfortable, and easier to drive every day, and everywhere.

So that’s where the value proposition sits, basically. You’re buying a supercar that’s also a kind of Rolls-Royce adjacent luxury cruiser. Two cars for one price. Bargain. Kind of. It also weight 2.5 tonnes, if you’d like to think of it in dollars per kilogram.

Oh, and it’s hand made, too, and genuinely feels like it.

For that money you get an incredibly posh and plush cabin, excellent seats, and everything you touch, and smell, seems expensive and refined.

The newly facelifted, and butt-lifted, Continental also looks simply stunning, from every angle, outside. Particularly in its new 'Tourmaline Green' paint (there are 18 standard colours to choose from, or you can have bespoke paint made for you on request). And 15 standard leather hide colours as well.

It comes with all the apps and connectivity you could wish for, including a Bentley App Studio.

This new ‘4Matic’ all-wheel-drive SL63 features AMG’s (M177) 4.0-litre twin-turbo V8, superseding the previous rear-wheel-drive SL’s similarly configured 5.5-litre unit.

Hand built by one AMG technician from start to finish, it produces 430kW (around 580hp) from 5500-6500rpm and 800Nm across a broad plateau from 2500-5000rpm.

It’s something of a mechanical masterpiece, and the previous seven-speed auto transmission, driving the rear wheels only, has been replaced by a nine-speed dual-clutch auto (with wet multi-disc start-off clutch) sending drive to all four wheels via Merc’s ‘4Matic’ AWD system.

There is some sadness that the world’s biggest producer and promoter of 12-cylinder engines has cut production of them altogether - the epic W12 is no more - and this does feel, on a smaller scale, like Porsche ditching flat-six engines forever.

Previous hybrid efforts from Bentley, including a V6-based one that the company now admits was a bit limp wristed, might cause some concern when you hear that Bentley will, henceforth, make just one engine for all its cars, and that it is a hybrid, albeit one attached to a 4.0-litre twin-turbo V8.

But then they point out the version in this Continental GT Speed’s is “the most powerful Bentley engine ever” and that sounds pretty good.

The engine alone makes 441kW and 800Nm, which almost sounds ample, but the addition of the electric E-motor is good for another 140kW and 450Nm, with the aid of a 29.5kWh battery, which somehow adds up to a combined output of 575kW and a nice, round, and impressive 1000Nm of torque.

All that power does have to move 2.5 tonnes of precious metal, which sounds like an ask, but is effortless in practice - hurling the Speed to 100km/h in a properly supercar-like 3.2 seconds on its way to a top speed of 335km/h.

Yes, vitally, it sounds pretty damn impressive when all the power sources are going at once, it even barks and pops on the overrun, a bit like the Porsche Panamera with which it shares the hybrid set-up, only a bit bossier, and perhaps classier.

The point of the hybrid feels like it’s mostly about performance and excitement, but it has a practical side, too, because in EV-only mode this giant Bentley can drive for up to 81km in pure, and slightly inappropriate-feeling, silence (at speeds of up to 140km/h).

Handy if you live in global cities with zero-emission zones, or if you want your neighbours to think you care about the climate.

One brilliant thing about this plug-in hybrid is it’s set up to use the engine to regen the battery, hard, in 'Sport' mode, so the more fun you have, the quicker the battery charges. So much so that, realistically, you might never need to plug it in at all (Bentley recently ran the car at a race track for two weeks and never needed to top it up via cable once).

It is an impressive, sonorous and enjoyable power plant, and you’d expect nothing less from Porsche, although Bentley says it’s done lots of work on the donor engine to make it uniquely more wonderful.

Mercedes-AMG’s official fuel economy number for the SL63 on the combined (WLTP) cycle is 13.9L/100km, the 4.0-litre twin-turbo V8 emitting 319g/km of CO2 in the process.

On the roughly 300km launch program we covered urban, B-road and some freeway running, returning an (indicated) average of 17.5L/100km. And that reflects some enthusiastic driving along the way.

The fuel tank requires 70 litres of 98 RON premium unleaded to fill it which translates to a theoretical range of around 500km, dropping to 400km using our real-world number.

While the top-line figures for performance hybrids like this always sound impressive, it’s hard to believe anyone will ever get near them in the real world, because the temptation to drive a car like this hard and fast, as its makers clearly intended, will mean chewing fuel in a very non-efficient way indeed.

On paper, though, where it matters in terms of being allowed to sell your giant luxury grand tourer in Europe, the Bentley Continental GT Speed produces just 29 grams of CO2 per kilometre. 

Fuel economy is a claimed 10.3 litres per 100km, which is optimistic, but still a lot lower than the equally unlikely 14L/100km figure for the old (12-cylinders and no hybrid) car. As in, neither car would ever achieve the theoretical figure, but at least the new one is clearly a lot better.

I recall driving the AMG SL65 around the backroads of Tassie a few years ago and that twin-turbo V12 monster famously packed 1000Nm of torque, while this car ‘only’ has 800.

But there comes a point where enough is enough… and this is enough!

With maximum torque available from 2500-5000rpm and peak power (430kW) on call from 5500-6500rpm there’s always stupendous acceleration available with a squeeze of your right foot.

Claimed 0-100km/h time is supercar fast at 3.6 seconds, while top speed is a toupe-troubling 315 km/h. And that’s electronically limited!

A typically ferocious engine noise and howling exhaust note accompany rapid progress and shifts from the nine-speed dual-clutch transmission are quick and positive, not to mention especially enjoyable using the steering wheel-mounted paddles.

There are six ‘AMG Dynamic Select’ drive programs from Comfort through to Race, the latter including a Drift Mode, which we didn’t experiment with. Nor did we dip into the ‘AMG Track Pace’ system for circuit-focused mapping and timing

However, far from drifting, the grippy Michelin Pilot Sport 4S rubber (275/35 fr - 305/30 rr) plants the car securely with the all-wheel-drive system and electronic locking rear diff playing their part.

I found the perfect set-up was in the ‘Individual’ mode with the engine, transmission and steering in racier settings and the suspension in ‘Comfort’. The adaptive damping in this configuration mixes smooth ride compliance with sharp dynamic response.

The car’s aluminium space frame chassis is part of a body structure mixing aluminium, magnesium, fibre composites and various strength steels.

Torsional rigidity is claimed to have been improved by 18 per cent and despite the lack of a roof the SL feels tight and solid.

Suspension is by alloy double wishbones front and rear with adaptive damping and active hydraulic anti-roll stabilisation standard (so, no physical anti-roll bars).

At the same time the 4Matic AWD system is able to vary torque distribution up to 100 per cent to the front or rear axle depending on where drive can be put to best use.

The speed sensitive, variable ratio, electronically controlled steering is accurate and turns in beautifully with good road feel. No doubt assisted by electric rear steering able to adjust the angle of the rear tyres by up to 2.5 degrees.

All this adds up to a hugely impressive package that, despite its 1970kg kerb weight, feels agile, athletic and able to attack corners like an overgrown hot hatch, putting its power down with unwavering authority.   

While indecently fast the SL63 can also stop rapidly with the AMG high-performance braking system standard. 

Huge composite ventilated and cross-drilled discs (390mm fr - 360mm rr) are clamped by six-piston fixed alloy calipers at the front and single-piston units at the rear. They wash off speed calmly and consistently with perfect pedal feel.

Even at highway speeds, particularly with the windows up, normal conversation is easy with the roof down. But if you need to raise (or lower) it, the operation takes 15 seconds and is possible up to 60km/h. 

Under the heading of miscellaneous observations, the turning circle is a not insubstantial 12.8m, so beware in the car park.

A front axle lift function is a welcome standard feature, raising the car’s nose 30mm with the press of a button. And lift locations are stored in GPS data, so the car will subsequently remember to lift itself at the same place, even if you don’t! 

Heating and cooling for the front seats combined with the heated steering wheel and Air Scarf neck warming makes winter top-down driving a pleasure.

The digital instrument display is not only crystal clear, it can be changed through multiple configurations, including a tunnel-like graphic for engine revs as well as specific readouts for speed, g-force, the lot.

At the same time, the central media screen’s angle can be adjusted to better cope with reflections and the windscreen wiper system Merc calls ‘Magic Vision Control’ channels fluid along the wiper arms onto the rubbers, which isn’t new, but works spectacularly well here.  

In an ideal world, one would take the Bentley Continental GT Speed for an appropriate drive from the top of Germany to the bottom of Italy or France, but instead we were asked to drive the big beast around a tight and slightly terrifying private members race track outside Tokyo called the Magarigawa Club.

Members here pay US$1 million a year for access to this circuit, carved out of several mountain tops, which features two long and fun straights attached to what feels like a hill climb circuit with a bit of Laguna Seca’s Corkscrew and a touch of Mt Panorama’s undulations.

This track, with its daunting lack of run-off, should have been an intimidating and possibly inappropriate place to try the Continental GT Speed, but it is a credit to the car’s “everyday supercar” personality that it soaked up the pressure, and pace with ease.

On our first lap we were encouraged to drive in EV mode, which was predictably a bit dull, quiet and not-quite boring, because if you went past 75 per cent of throttle, or 140km/h, the engine would kick in and things would instantly get interesting.

It was a good chance to note just how lushly comfortable the cabin and seats are, however, and just how supple the suspension can be.

The Bentley’s “secret weapon”, according to its engineers, is a new twin-valve damper the allows the chassis to behave like a sports car when you want it to - probably about 3.0 per cent of the time for actual owners - and an absolute luxury pleasure palace for cruising around the rest of the time.

The split personality thing really is on offer with this car, as we found out once we engaged the Sport setting.

The Speed’s all-wheel drive, all-wheel steering, torque vectoring and electronic LSD were all on display over the later laps, in which we were allowed to blast past 200km/h and find out just how good the brakes are at pulling up 2.5 tonnes of high-speed luxo-barge.

You do your steering via a lovely wheel with a leather front and Alcantara wheel, and it feels effortless, even in full track attack mode. A bit more feedback might be nice, but I guess Bentley owners have other cars for that kind of thing.

Aside from the rushing, roaring speed, what is most impressive is how little body roll there is from the Continental. It feels planted, poised, happy to change direction and is rarely upset or flustered, despite some squeals of complaints from the tyres. 

Getting too wide on to the ripple strips caused a shudder and a skip sideways now and then, but perhaps I shouldn’t have been so far off the racing line.

Overall, the Continental GT delivers on its name, with Speed, and lots of it, all delivered in a properly swanky environment.

All the money and you only get four airbags; front and side for driver and passenger. And none in the back, so don't sit there. Bentley also has its own 'Safeguard' suite of technologies including 'Advanced 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'.

The SL63 4Matic+ will be covered by Mercedes-AMG’s five-year/unlimited km warranty, with roadside and accident assistance included for the duration, both of which are expected in this category. 

Maintenance intervals are 12 months/20,000km, and a fixed-price service plan lists an average of $1583 for each of the first three visits to the workshop. Not exactly small change, but not unheard of in this part of the market.

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.