Mercedes-AMG GT 4-Door

	Mercedes-AMG GT 4-Door
	Debut: 2018 Maker: Mercedes-Benz Predecessor: No

Published on 28 Nov 2018

A revamped CLS? The AMG GT 4-Door is far more than that.

Although the AMG nameplate has been existing for half a decade, it became part of the Mercedes organization only since 1999. 10 years later, it built its first dedicated model, SLS. 4 years ago arrived the second model, AMG GT. Both SLS and GT managed to establish a good reputation for the performance brand, good enough to be seen as an equal of Porsche. However, when it comes to profit, they contribute little, or none. AMG still earns its living by modifying Mercedes’ production saloons, wagons and hatchbacks. Is there room for a more mainstream AMG exclusive model? AMG believes yes, and we have no reason to doubt. Considering Porsche can convert a VW Toureg into Cayenne and Audi Q5 into Macan, there should be plenty of rich customers wanting to buy something more useable than sports cars yet preserving the performance image of AMG. So, here comes the AMG GT 4-Door.

Make no mistake, the AMG GT 4-Door is by no means the stretched and 4-door version of the AMG GT. Far from it actually. While the GT sports car is constructed out of a dedicated front-mid-engined layout and an aluminum spaceframe chassis, the 4-Door is built upon the MRA platform of any large Mercedes sedans, the closest of which is CLS. It shares a similar, 4-door coupe body profile and essential mechanicals. Now you may question: doesn’t it clash with the CLS in market positioning? Somewhat yes, but Mercedes limits the damage by reassigning the CLS a lower position, while the AMG GT 4-Door sits above it. That is why the new CLS has lost the range-topping ’63 model and a large part of its attraction. Over time, I’m afraid the CLS will become the casualty of AMG GT 4-Door. Its future is bleak.

It is weighty, but the chassis is stiffer than that of the CLS.

The 4-Door employs a steel-aluminum hybrid monocoque similar to that of the CLS, but it is strengthened by an aluminum plate under the engine and 3 braces across the transmission tunnel. Like its sibling, the bonnet and front fenders are aluminum sheets. The rear bulkhead and boot floor are converted to lightweight carbon-fiber reinforced plastics, but still, the car is heavier than the CLS. A six-cylinder mild-hybrid CLS53 weighs 1905kg. The equivalent GT 4-Door is 65kg heavier still, pushing it to the edge of 2 tons. Meanwhile, the flagship ’63 S model tips the scale at 2045 kg. If Ferrari or Aston Martin build such a car, I think they could be 200kg lighter yet have a better weight distribution. That said, the AMG is comparable to a Porsche Panamera in terms of weight – if not rear seat accommodation, since the Porsche does not have such a swoopy roof line.

Fortunately, AMG knows how to style the car to appeal. The 4-Door looks handsome, fast and special. It employs AMG’s trademark “Panamericana” grille, which looks fire-breathing. Its fastback form is different from the 4-door shape of the CLS, while its tailgate gives easier access to the load bay. Interestingly, the combination of its round tail, fastback and shallow side windows gives an impression of a modern, 4-door version of Porsche 928. Porsche should have given the Panamera a shape like this, shouldn’t it?

As for aerodynamics, the car employs active air panel up front and a multi-stage retractable and extended rear spoiler. For even more downforce, you may opt for a fixed (but manually adjustable) rear spoiler.

Porsche should have given the Panamera a shape like this, shouldn’t it?

The car offers 4 models: both the entry-level GT43 and GT53 employ Mercedes’ new 3-liter straight-6 with one turbo, one electric charger and EQ-boost mild hybrid assistance, which offers a short boost of up to 22hp and 184lbft. The petrol engine produces 367hp on GT43 or 435hp on GT53, equaling to those of CLS450 and CLS53. Meanwhile, both GT63 and GT63 S employ the familiar 4-liter V8 with a pair of twin-scroll turbos and cylinder deactivation. They produce 585hp/590lbft and 639hp/664lbft, respectively – the latter surpasses E63 S by 27hp and 37lbft, thanks to remapped ECU and the use of ball-bearing turbos. The 6-cylinder motor partners with conventional 9G-Tronic automatic, while V8s pair with AMG’s own 9-speed MCT multiplate clutch transmission. Their top speeds are 168, 177, 193 and 196mph, respectively. 0-60mph takes 4.7, 4.3, 3.3 or 3.1 seconds. This means, the GT63 S is the fastest accelerating ever AMG model, more so than E63 S and AMG GT R !

The suspensions and steering are essentially the same as those of CLS, but the calibration is sportier, of course. All models employ the rear-biased 4matic+ system with rear-drive Drift mode as you can find on E63 S. The 6-cylinder models use steel spring suspension with adaptive dampers, whereas V8s employ air suspension. 4-wheel steering, first used on the AMG GT R, is standard on the V8s, but only the flagship GT63 S gets active rear differential and adaptive engine mounts. In terms of performance equipment, the AMG 4-Door offers everything you can dream of.

The only visual link to the GT sport car is the flashy, prominent transmission tunnel.

The Mercedes interior is rich and elegant, of course, but it is largely the same as that of the CLS or E-class. The only noticeable difference is the flashy, prominent transmission tunnel, which provides the only visual link to the AMG GT. The rear cabin can be either a bench seat for 3 or 2 individual seats. Legroom is good. Headroom is less so, but enough for six-footers.

In normal driving with the suspension setting in Comfort mode, the GT 4-Door is a rather civilized machine. It rides nicely, if not as good as the CLS on harsher surfaces. It cruises smoothly and quietly at speed. Even in Sport mode, the suspension is firm but not uncomfortable.

However, the chief mission of this car is to entertain, and it is glad to do so. The GT53 might not be as hot as the V8 model, but it offers sufficient power to entertain. The straight-six motor is smooth, its power delivery is linear and the 48V electric motor provides the necessary boost at the low end. Moreover, its exhaust note is musical, something getting rarer and rarer these days. However, the GT63 S lands on a different level. Its ability to accelerate is incredible, not far from the level of supercars. Its V8 is a gem, trailing only Ferrari’s V8 for minimum lag and quick throttle response, producing a deep-chested roar at rev and crazy crackles on overrun. Yet with 4-wheel drive and the responsive MCT gearbox, the V8 lays down its power efficiently to the road, converting to kinetic energy without fuss. The titanic mid-range torque, 664 pound-foot, is eye-opening, easily masking the weight of the car. Unquestionably, this is the world’s fastest 4-door 4-seater.

This is the world’s fastest 4-door 4-seater, also one of the most entertaining to drive.

However, what makes the AMG GT 4-Door a dedicated AMG model rather than a modified Mercedes is handling. Traditional AMG cars were more about straight line speed than cornering. Although the recent E63 S with rear-biased 4matic+ system has changed that impression, it is still not as good to handle as, say, a BMW M5. What the AMG GT 4-Door excels over its sibling is the way its various systems are integrated and calibrated – the 4matic+, the active diff, rear-wheel steering, air suspension and stability control. They are more in a piece to deliver more grip, more poise, flatter body control, keener turn-in… in short, it feels more agile and more controllable. The addition of 4WS really helps it to turn in tighter corners. The steering and brake pedal provide great feedback, something you can’t say on the E63 S. The steel brakes are powerful, good enough to withstand a few laps of track abuse. As a result, you can trust on the car and all its controls. In corner, the car displays a neutral balance, with just a hint of stabilizing understeer. Stability control might be working behind the scene, but it is undetectable. When the car approaches the limit, it slides progressively and predictably, which is another improvement from the all-or-nothing E63 S. Rear-wheel steering certainly helps it. The power slide here is easier to catch and to extend than an M5 or Panamera as well. AMG has done a great job to make the 4-Door a world-class entertainer. You might find more agility and thrills from a smaller car like Alfa Romeo Giulia QF, but for something as big and luxury, the AMG is unbeatable.

The only question is pricing. The GT63 S costs £135,000 before options. Even the GT53 demands £90,000, which can buy you an M5 Competition. Then again, the AMG GT 4-Door is a niche product, more special to look and to drive. And certainly the people on street won’t confuse it with a regular E-class or CLS.

Verdict:

Published on 14 Nov 2022

GT63 S E Performance

Plug-in hybrid makes AMG GT 4-door astonishingly quick.

Mercedes-AMG GT63 S E Performance, what a long name! Previously, this car was widely tipped to be called "GT73e", which sounds fantastic to me. However, AMG wants to promote the new “E Performance” label, which will be used to badge all its electrified models in the future, so the flagship GT 4-door has to be compromised. Although not using a higher number, the E Performance version of GT63 S sits at a higher performance level than its conventionally powered sibling. It commands an eye-popping £174,000, £30K clear of its lesser sibling as well as the top Porsche Taycan Turbo S, Panamera Turbo S E-Hybrid and BMW M5 CS. In the performance 4-door world, this is as expensive as you can get.

The new flagship sprints from rest to 62 mph in 2.9 seconds, 0.3s less than the former range-topper. Moreover, AMG claims 0-124 mph in less than 10 seconds, which is as quick as a Porsche Taycan Turbo S. Top speed, however, remains unchanged at 196 mph, implying its electric power cannot sustain high-speed run.

The E Performance model keeps the 4-liter twin-turbo V8 intact, still producing 639 hp and 664 lbft of torque, driving through a 9-speed MCT gearbox and 4matic+ system to all four wheels. What's new is the rear axle. A new EDU (electric drive unit) combines the function of 3 – an electric motor, a 2-speed gearbox and electronic LSD – in a compact package. The electric motor can produce up to 204 hp and 236 lbft of torque. Thanks to coupling it to a 2-speed gearbox, which switches to 2nd gear when the motor revs to its limit of 13,500 rpm at around 87 mph, the power delivery can match that of the V8. This means total power is simply the summation of the two, i.e. 843 hp. Combined torque, however, is even higher than the sum of two, at 1033 lbft (1400 Nm), thanks to different gearing.

Rear-mounted battery and EDU improve balance but add 260 kg and raise CoG.

Meanwhile, a lithium battery is mounted above the rear axle, which improves front-to-rear balance from 54:46 to a perfect 50:50., if not center of gravity. AMG said the inhouse-built battery has very high power density, which can supply 95 hp continuously or 204 hp for 10 seconds. Anyway, it still weighs some 89 kg. In addition to the EDU, the whole car weighs 2305 kg, or 260 kg more than the GT63 S. The electric power normally drives the rear axle directly. Only when special circumstances require the 4matic+ system will let the electric power flows forward through mechanical connection.

The E Performance, as suggested by its name, is performance rather than environmental-oriented. Its battery might have a high power density, but not energy density. Its capacity is only 6.1 kWh, giving a zero-emission range of merely 12 km or 7 miles. You may charge it at home, but I doubt who would do so for a range not sufficient to take you to a supermarket nearby and return. However, it is sufficient to deceive WLTP test cycles, reducing emission from 293 to 196 g/km.

The rest of the car undergoes very few changes. There might be minimal retuning to the adaptive air suspension to compensate for the extra weight, and the standard fitment of ceramic brakes, but otherwise the hardware is just the same.

Outright dynamics is not quite as strong as its ICE sibling, but you need to drive on a track to realize.

On the road, the hybrid model is not a huge difference, but acceleration from the low end is noticeably stronger. It picks up speed as if a supercar, hugely admirable for a car so big and heavy. Meanwhile, the aural excitement of the AMG V8 is kept intact. The car also handles its mass in corner extremely well. Traction and grip are huge, body control is tight, stability is high, and steering is accurate.

However, on a track, push the car to the extreme for extended time, and the laws of physics are finally exposed. You start feeling the extra mass in earlier understeer and tires overheating, so that you need to back off earlier before corner. The ceramic brakes remain strong under repeated hard use, but the regenerative braking compromises its pedal feel. In fact, AMG’s technical boss admits that the pure combustion GT63 S has stronger outright dynamics. This might explain why AMG does not reveal its Nurburgring lap time. Perhaps it is also why the firm opts not to name it GT73e.

Verdict: