Mercedes-Benz AMG GT vs McLaren 720S

What's the difference?

The GT63 4Matic+ is a breathtaking example of everything that Mercedes-Benz and AMG are.

Ferociously fast, incredibly agile and superbly sophisticated, it should be on anybody’s shortlist, if that also includes a Porsche, Aston Martin, Maserati or even a Lamborghini. And it’s definitely much more than yesterday’s SLC ever was – for similar money in today’s terms, as it turns out.

But, around Tasmania’s glorious roads at least, the Mercedes-AMG lacks the ride comfort and road noise isolation to be a fully-rounded-out GT, and that’s a disappointment for a brand with such formidable history in making such cars.

Past McLarens have been accused of being a bit soulless, but this one is alive. The last time I felt like this in a car was a Ferrari F12, one of the scariest but most brilliant cars I've ever driven. Except the 720S isn't scary on the road, just sheer genius.

The 720S doesn't necessarily beat the competition but it opens up new ways of doing supercar things. It's a car that looks amazing, is more than fit for purpose but has a wider range of talents than the others. 

That makes it ever more compelling, both as a piece of automotive brilliance to admire, andl as something to consider when you've got half a Sydney apartment to spend on a car.

Australian roads await, but the drive through rural English country roads and villages was a great preview. All I can say is: gimme one.

This is still clearly a Mercedes AMG GT coupe, like the 2014 C190 original, but a ground-up redesign sees it subtly yet significantly altered.

Some 270kg heavier than before, the larger-in-every-dimension body combines aluminium, steel, magnesium and fibre composite materials for improved rigidity and a lower centre of gravity. Length (4729mm) and wheelbase (2700mm) have been stretched by 177mm and 70mm respectively. Width (1984mm) and height (1352mm) are also up.

The nose treatment is similar to before, especially with the bulgy bonnet and signature vertical slatted grille fitted. These, combined with the LED digital headlight shape effect, is reminiscent of, but far-better executed than, the goofy-looking MG5’s face.

Underneath, it's an all-new platform shared with the SL, with the rear transaxle of the old car replaced by a permanent AWD system, leading from 46:54 front/rear weight distribution to 50:50 as a result.

That aggressive, exaggerated cab-backward/ultra-long bonnet silhouette that visually connected it with the SLS gives way to more-conventional and practical coupe proportions that is striking if not especially original, since they do look quite 911-esque. Along with the longer wheelbase and wider tracks, the result allows for two small rear seats to be fitted, while liftback cargo access remains.

Similarly, in the name of way-more usable interior packaging, Mercedes-AMG says it pushed the driving position nearly 180mm forward compared to the previous GT. Let’s see what that all looks like inside.

The 720S has received mixed reviews but nobody will say it isn't striking. I love it - every designer says their influence is a Lockheed SR-71 Blackbird (designer Melville even jokes about it), but you really can see it in the 720S, especially in the cockpit design, which looks like a glass canopy from that surveillance jet.

McLaren's signature dihedral doors, which go all the way back to the 1994 McLaren F1, are substantial, with a double skin to act as a serious piece of aero kit.

Melville told me in January that he thinks the cars look shaped by nature, using the example of a stone left in a stream to erode. The 720S is full of details evoking that image, with a clean, taut surface. Where everyone complained that the 12C was "designed in a wind tunnel", the 720S looks designed by the wind. In the carbon and aluminium, it looks extraordinary.

One of the most talked about features are those headlights - almost always finished in black, they're known as "the socket". When you get close you see slim LED DRLs, small but powerful headlights, and you then discover two radiators behind them. Follow it through and the air exits through the bumper, around the wheels and then through the door. It's quite something.

Inside is the McLaren we've come to know and love, but with a clever kicker. The dash panel looks lifted from a race car - but with far nicer graphics. Switch to "active" mode, turn everything up to Track and the panel swings down and presents you with a minimised set of instruments to reduce distraction and make up for a lack of head-up display - just speed, get and, revs.

The first impression inside is that of space, despite the falling roofline and coupe-like upsweep of the side windows and you look back. While, again, similar to a 911s, a kink at the door gives the GT a unique character.

Even larger people will appreciate the generous amounts of room up front, with space to stretch, sat in sumptuously comfy bucket seats. Note that the standard ones are better than the racier but firmer Sports versions.

The driving position is perfect, ahead of a dashboard that is very typical modern Mercedes in appearance and layout.

To that end, the tablet-style integrated touchscreen (11.9 inches) is clear, fast and intuitive once time is taken to learn it. And points are also won for the multi-configurable electronic instrumentation, that allows for a variety of screens, including track, classic and minimalist views.

The trademark turbine air vents, the quite beautiful material and trim finishes and just the general solid feel are further typical contemporary Mercedes cabin treatments, as are the excellent ventilation and ample storage options.

And while rear vision isn't great, that's what cameras are for. It's all pretty much on brand.

It is a shame, given how elevated the Mercedes-AMG engineering is underneath, that the GT’s interior look and ambience is so similar to those of a (albeit higher-spec) C-Class or GLE. It's simply not as special as some of the company’s previous sports cars.

More annoyingly, the ride is too firm and bumpy for a GT, and this has the unhappy effect of provoking random rattly trim sounds within the cabin. It’s a bit like scrunched-up cellophane. In a $420K (as tested) Merc, that’s very disappointing, especially as it can be heard over the copious amount of road and tyre noise droning through, particularly on coarser bitumen surfaces.

Further back, the rear seat is strictly two-plus-two, and nobody over 150cm tall is recommended to travel there by Mercedes itself. That sloping roofline is the culprit. That said, brief trips with a bowed head are possible, as the fixed cushions and split-folding backrests are actually surprisingly comfy. But only for short journeys. Kids should love it though, and the second row does open up the GT’s usefulness enormously.

As does a near-doubling of the AMG’s cargo capacity, jumping 146 litres to 321L with backrests erect, to a whopping 675L (+325L) in two-seater mode. The flat floor is accessed via a large electrically-operated liftback door, offering quite a large aperture for easy loading/unloading.

Having no spare wheel helps here, with a tyre inflation kit included in lieu of that.

Meanwhile, at the front, under the bonnet, things have definitely changed for the better as well.

For a supercar, there is a surprising amount of space in the cabin. You can strap 220 litres of (hopefully) soft stuff on the rear shelf behind the seats and there's a 150-litre boot under the nose. You can store your track gear under there, including helmet, or even cram in a few soft bags for a weekend away.

Again, unusually a for a supercar, you're also  treated to a couple of storage cubbies in the centre console.

There's plenty of room in cabin for two bodies and the driver's seat offers lots of adjustment. Despite being so close to the front wheels, your feet have space even for my ridiculous duck feet to fit easily. There's even enough headroom for those over six feet, although the glass portholes in the top of dihedral doors might not be so welcome in an Australian summer.

Kicking off at $489,900 plus on roads, it's fairly clear that the car the local operation has in its sights is the Ferrari 488 GTB, which sells for around $20,000 less but rarely arrives with less than $40,000 in options on board. Two further versions of the 720S are available from $515,080, the Luxury and Performance spec levels, both largely cosmetic.

The 720S ships with 19-inch front wheels and 20-inch rears wrapped in Pirelli P-Zeros. The exterior is finished in "dark palladium" trim and the cabin is lined with Alcantara and Nappa leather. Also onboard is a four-speaker stereo, digital dash, dual-zone climate control, sat nav, active LED headlights, power windows, sports fronts seats and not much else.

A predictably lengthy options list includes paint from $0 to $20,700 (McLaren Special Operations, or MSO, will cheerfully find ways to charge you more for that extra special paint job), but most of the list is carbon fibre bits, reversing camera ($2670!), a $9440 Bowers and Wilkins stereo... you get the picture. The sky, or your credit card, is the limit.

The front lift kit is $5540 and totally worth it to protect the underbelly from driveways. Unlike a couple of Italian rivals, it's not mandatory for all speed-bump ascents.

As we discover every time we look at a car like this, the spec seems slim but none of its competitors have much in them, so it's line-ball.

There’s a plaque signifying which engineer “handcrafted” the GT’s engine – in this case, the famous M177 in 3982cc, 4.0-litre twin-turbo intercooled V8 petrol guise.

Delivering 430kW of power at 6500rpm and 800Nm of torque from 2500-4500rpm, it sends drive to all four wheels via a nine-speed multi-clutch transmission (dubbed MCT in AMG-speak), catapulting the GT63 4Matic+ from 0-100km/h in just 3.2 seconds, on the way to a top speed of 315km/h.

How does it do that?

With AWD, the GT is now nearly 15 per cent heavier than before, but it still manages a punchy 218kW/tonne. Active aerodynamics over, inside and under a more-rigid body structure also helps.

The AMG 4Matic+ AWD system goes from 50/50 front/rear, to 100 per cent rear, variable torque distribution according to conditions and settings, and backed up by an electronic limited-slip differential. Among the many driving settings are Race Start, Drift Mode and good-old Comfort, if it all becomes too much.

Also keeping all that performance in check is a high-performance composite brake setup with improved cooling for faster responses.

Interlinked active roll bars improve body control, the five-link independent suspension features adaptive dampers for a softer ride.

And, as for that 4WS tech, the rear wheels steer opposite to the fronts at up to 100km/h (by some 2.5 degrees) for tighter and tidier handling, or 0.7 degrees in the same direction above 100, for greater stability and road-holding.

Its effect on the way this near-two-tonne coupe zigs and zags around corners is something you need to experience to really appreciate.

The 720S runs a 4.0-litre version of McLaren's familiar flat-plane crank twin-turbo V8. Power is up to 537kW (or 720PS, hence the name) and torque up almost 100Nm to 770Nm, from 678. McLaren says 41 percent of the components are new.

A seven-speed twin clutch sends power to the rear wheels and the 1283kg dry (down 106kg from the 650S) monster hits 100km/h in 2.9 seconds, surely a cautious claim. The more alarming 0-200km/h clam is a terrifying 7.8 seconds, half a second quicker than its closest rival, the 488 GTB. That is seriously, insanely quick, while top speed is equally bonkers at 341km/h.

Instead of a complicated and heavy active differential, the 720S uses the rear brakes and various other methods to get the same effect. It's one of several ideas pinched from F1, some of them now banned.

Actually, the GT’s economy isn’t horrendous considering how fast it can go.

Even blasting a few times around beckoning country roads, we managed an indicated 13.0L/100km, which is an improvement on what Mercedes-AMG says the GT averages the 14.6L/100km average that Mercedes-AMG officially states.

That translates to a carbon dioxide emissions rating of 334g/km.

Using 98 RON premium unleaded petrol, an average of just under 480km between refills of the 70L tank is possible. The urban run sees consumption rocket to 21.8L/100km (for just 321km of range), or 10.4 out on the highway run, meaning that over 670km is possible should you decide to drive in a docile manner.

McLaren claims the European combined cycle could return 10.7L/100km, but we have no way of knowing if that is accurate because we weren't mucking about on the day we had the car.

Nobody will drive the GT63 4Matic+ and think, ‘Oh, this is OK’, because its breadth of performance is phenomenal.

No matter which mode you're in, from Comfort through to track-tuned Race, the Mercedes-AMG blends forceful pace and commanding control without ever breaking a sweat.

Flex your right foot and the two-tonne coupe bounds into action like a giant on a mission, striding past posted speed limit signs in nanoseconds and way, way faster than the law will stand if diligence isn’t exercised.

And there’s no point relying on seat-of-your-pants sensations, either, because the chassis below embraces the road with an almost zealous devotion. Which is astounding, given how agile the four-wheel steering-enhanced handling is.

The 63’s super power is exactly that – it dulls your sense of speed. One tester admitted to exceeding 150km/h before noticing. An odd confession considering the sonic boombox that is the bi-turbo V8’s howl.

But jailbait performance is not even the 63’s most lingering joy. That would be its steering perfection, that delivers that rare trifecta of keenness, crispness and communication. The wheel feels eager and alive in your hands, even when powering between tight turns, backed up by sensational grip and control. How can a two-tonne GT handle so sharply?

Warm, dry roads were the order of the day, so we can’t tell you how the 4Matic+ permanent AWD system deals with wet or slippery surfaces, but the slick multi-clutch transmission, seamless torque-vectoring tech and sticky tyres more than cope with the 63’s formidable outputs.

So, that's the gushing part out the way, then.

Despite the adaptive dampers, rigid architecture and exquisitely sophisticated suspension, the ride is simply too stiff in Comfort mode, and downright jittery on some of the Tasmanian roads we tested on, for the 63 to be considered a true luxury grand tourer. It just isn't comfortable, luxurious or supple enough.

Plus, grippy as they are, the 21-inch wheels transmit too much road and tyre noise through to the cabin, meaning that the GT isn't as quiet as you'd hope. Add the aforementioned trim squeaks, and the expected cocooned silence isn’t always there.

The upshot is that the 63 possesses more of a sports car character than a luxury GT character. Great news if you're a 911 type buyer and are seeking a high-performance 2+2 alternative, but a disappointment if comfort and refinement are priorities.

Still, it is impossible not to be deeply moved by this Mercedes-AMG.

One of the biggest changes from 650 to 720 is the new Monocage II carbon fibre tub. The drop in overall weight is partly because the cage now includes the windscreen hoop, which previously was metal. Kerb weight with all fluids and a 90 percent full fuel tank (don't ask why 90 percent, I don't know either) it weighs 1419kg, giving it the same power-to-weight ratio as a Bugatti Veyron. Yikes.

The 720S is an astonishing car. We always say you can pootle in a modern supercar, but the 720S is so user-friendly, maneouvreable and so easy to see out of - there are no significant blind spots with an almost entirely glass roof - you can tackle city and country in comfort mode and actually be comfortable. Comparatively, a Huracan goes all blergh in Strada mode and the 488 GTB never stops begging you to kick it in the guts. The McLaren is easy, liveable and smooth. 

I was driving a left-hand drive car in the UK, which should have been a complete nightmare, but it was fine - the vision is excellent, particularly over the shoulder. 

But when you do decide to kick the 720S into action, it's wild. The acceleration is brutal, the handling impeccable and the ride, oh, the ride. No supercar can handle bumps, irregularities and flat out poor surfaces like the McLaren. The 540C's ride is incredible as it is, but the 720 is just wow.

Because it's quite light, the nose goes where you point it, the huge brakes have less to stop, the towering power less to push. The steering in the 720S is well-weighted but has tons of feel - you know what's going on underneath the double-wishbone sprung front wheels and you can adjust what you're up to accordingly. The stability system is excellent, too. Never overbearing or abrupt, where talent ends and the help begins is delightfully blurry.

The new engine is a bit more tuneful than past McLarens - there's even a loud-start party trick - but it's not loud and overbearing. You'll hear turbos whisting, sighing and pshawing, a deep bassy exhaust note and some awesome intake roar. But there's not much off-throttle character. It does at least do away with the histrionics of the Italians.

The only serious drama is the amount of noise bouncing around the cabin over about 100km/h. There's a lot more glass than sound-soaking Alcantara, which explains some of the extra tyre racket over a 650S. You can't have everything, I guess.

Along with a super-strong carbon tub, to which is fitted aluminium crash structures front and rear, the 720S comes fitted with six airbags, stability and traction controls and carbon ceramic brakes with ABS (100-0 happens in fewer than 30 metres).

What’s the GT like to own?

Mercedes-Benz offers a five-year/unlimited km warranty, with five years of roadside assistance. This is average for most mainstream and luxury brands, but superior to most sports-car makers like Porsche and Lamborghini.

Intervals are every 12 months or 20,000km, and while no capped-priced servicing is offered on the GT, pre-paid three-, four- or five-year service plans are available, ranging from $5165, $7700 and $8665 respectively.

Big performance demands big maintenance bills, it seems.

The 720S comes with McLaren's three-year/unlimited kilometre warranty with roadside assist. McLaren will want to see you every 12 months or 20,000km, which is quite unusual at this level.