2019 Mercedes-AMG GT63 S performance review

On paper the 2019 Mercedes-AMG GT63 S is a tough sell.

At face value it’s a swoopier, sportier version of the traditional E63 S sedan, a car with which it shares its 4.0-litre twin-turbo V8, nine-speed automatic gearbox and 4MATIC+ all-wheel drive system, but at $349,900 the GT63 S is a full $100K dearer than its more sensible sibling. It offers an extra 20kW/50Nm as compensation, but it still seems a steep ask for shaving 0.2sec from the 0-100km/h claim.

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Dig a little deeper, however, and the GT63’s case becomes stronger. The chassis is based on the same Modular Rear-wheel drive Architecture (MRA) that underpins a whole heap of Mercedes models, but it’s been heavily re-engineered by AMG, the structure strengthened to improve response and handle the increased lateral loads.

The imposing body is 61mm longer, 36mm narrower and 13mm shorter (in height) than the E63 and there’s an extra 12mm of wheelbase. You can judge the success of the design for yourself, but it has massive presence – particularly as it’s a pretty massive car – and for some potential buyers that alone may be enough.

Others will be swayed by the greater level of personalisation offered. At this end of the market having a ‘bespoke’ car can be a big deal and combine the various paint, exterior and interior trim, wheel, leather and styling choices and you could theoretically build a couple of thousand GT63s before doubling up.

There’s even the option of converting the rear seat from a traditional bench to a pair of heavily reclined, heated individual chairs with their own central touchscreen. Fancy. To sit in and operate it feels more special than an E63 and sportier than an S63.

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For hardcore drivers there’s the possibility of a fixed carbon roof ($5900), carbon-ceramic brakes ($17,900) and Michelin Pilot Sport Cup 2 tyres ($1600), of which the latter two are fitted to our fully-loaded test car. Strange options for a 2045kg luxury limo, perhaps, but it’s those who would rather do 18 laps than 18 holes that this monster Merc is aimed at. Following the SLS and the GT Coupe, the GT four-door is just the third model solely developed by AMG and the naming connection to its two-door sibling is no accident.

The GT63 S might not be the most powerful AMG ever offered – that honour is retained by the 493kW/1000Nm SL65 Black Series – but it is the quickest. Housed under that sloping bonnet is the most powerful iteration yet of the 4.0-litre twin-turbo M177 V8 – so far, at least – which sends a whopping 470kW and 900Nm to all four wheels via a nine-speed wet-clutch automatic.

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With Race Start engaged, reaching 100km/h will take just 3.16sec providing you have a sufficiently grippy surface. Heathcote’s unprepped launch pad wasn’t, wheelspin triggering the traction control and consistently costing three tenths, hence the need to run in the opposite direction.

Beyond 100km/h the charge continues, 160km/h flashing by in 6.85sec, 200km/h in 10.67sec and the quarter mile conquered in 11.08sec at 203.43km/h. The latter is 0.2sec quicker than our best E63 S effort but the trap speed is virtually identical. This suggests the GT63’s wider rubber and shorter final drive (3.27:1 vs 3.06:1) give it an advantage off the line before the E63’s 165kg weight advantage helps it slowly stabilise the gap as speeds increase.

That said, a tenth here or there is academic as the GT63 is ballistically, ludicrously rapid. Triple figures are reached almost as quickly as your brain can recognise you’re moving but it’s the full-throttle punch in the back when accelerating from 160km/h or so that establishes the GT63’s autobahn-dominating credentials.

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As you’d expect from an AMG, the soundtrack is top-notch, an evil V8 snarl, though given its focus some extra GT R-style theatrics in Race mode wouldn’t go astray. The two turbochargers tucked in the vee of the engine now have anti-friction bearings on the turbine wheels to improve response and there is no lag whatsoever. Any throttle command is answered immediately.

The nine-speed MCT gearbox feels sharper, too. Upshifts are as rapid as ever but the downshift mapping seems more aggressive, the tacho needle jumping north of 6000rpm in response to requests from the left-hand paddle.

Speed is shed rapidly by the huge carbon-ceramic brakes – stopping from 100-0km/h requires just 33.84m – and their fade resistance in the face of extreme adversity somewhat justifies the near-$20K cost.

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So far we have a luxo limo that offers plenty of personalisation and is a rocket in a straight line, but it’s in the corners that the GT63 sets itself apart, setting a new standard for what’s possible from a four-door car.

Not for nothing is this beast the fastest of its kind around the Nurburgring Nordschleife with a 7min25.41sec lap, more than six seconds quicker than the Alfa Romeo Giulia QV and almost 13 seconds up on the Porsche Panamera Turbo.

Its footprint is enormous, with 21 x 10.0-inch wheels and 275/35 tyres up front and 21 x 11.5s at the rear wearing 315/30 rubber, while tracks are 20mm and 69mm wider front and rear respectively compared to the E63.

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The GT63’s trump card, though, is its rear-wheel steering which lends a freakish level of agility, particularly on corner entry. In conjunction with the sticky optional rubber the corner entry speeds this massive mound of metal is capable of defy belief.

Having the rear wheels turn in the opposite direction to the fronts up to 100km/h (at which point they turn in the same direction to aid stability) appears to dramatically lighten the load on the front tyres, for where you expect understeer there is none.

It rotates so incredibly well into the corner that before you know it full throttle is required, the variable all-wheel drive system loading up the rear tyres until they can take no more and then shuffling power to the front. The result is total traction with perhaps a hint of oversteer and a look of amused amazement on the face of the driver.

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There is a price to pay for this remarkable performance. The lack of grip on cold tyres is as alarming as the grip on warm rubber is impressive, the ride is generally fine but turns choppy over poor surfaces and the whole car feels unhappy in confined spaces.

Thumps from the gearbox and chatter from the steering and diff in tight turns are at odds with the premium image and while refinement is better than the E63 (a new mount for the rear diff aims to improve NVH levels and appears to work) tyre noise is an ever-present companion.

But such issues are easier to forgive in the GT63 because it delivers at such a high level when you drive the wheels off it. The E63 is impressive to a certain (extremely high) level, at which point its luxury sedan roots become evident, whereas AMG’s latest creation feels to have high performance in its DNA – it’s the most impressive, cohesive driver’s car Affalterbach currently offers and that includes the GT two-doors. Forget the on-paper stats, from behind the wheel the Mercedes-AMG GT63 S is actually quite an easy sell.

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2019 MERCEDES-AMG GT63 S SPECS
Engine: 3982cc V8, DOHC, 32v, twin-turbo
Power: 470kW @ 5500-6500rpm
Torque: 900Nm @ 2500-4500rpm
Weight: 2045kg
0-100km/h: 3.16sec (tested)
Price: $349,900 ($382,300 as-tested)

Like: Head-smashing performance; incredible dynamics; feels special
Dislike: Low-speed refinement; huge price

Rating: 4.5 out of 5 stars