Mercedes-AMG GT S, Porsche 911 Turbo, Front view 33 Photos Zoom

Mercedes-AMG GT S and Porsche 911 Turbo: The sports car dual of the year

Finally! The dual with GPS measuring device and 'buttometer': the Mercedes-AMG GT S squares off with the Porsche 911 Turbo in the test. The comparison of the year, and until shortly before the end we had no idea what the outcome would be.

With a smack, the suction cup of the GPS measuring device is positioned on the front windscreen, black tape, which in motorsports seems to hold together entire cars, now secures the flat antenna to the roof – the aluminium skin of the Mercedes- AMG GT S simply ignores its magnet. In the Porsche 911 Turbo it holds, as only its doors, bonnet and wings are made from aluminium. However, although the 911 still conceals all-wheel drive and steering beneath the classic shell, at 1,596 kilograms it still weighs 33 kg less than the AMG GT S. And it goes on: the porsche drive system offers more power and torque (513 HP/710 Nm) than the new four-litre V8 biturbo of the Mercedes AMG GT S (503 HP/650 Nm). Great.

The Mercedes-AMG GT S with a bear-like V8 biturbo

Whether or not this will decide probably the most exciting sports car dual of the still-young year before the first measurements are even taken? At least it doesn't immediately sound like the Mercedes-AMG GT S has given up without a fight. It grunts grumpily from its angular exhaust pipes, its bassy tone alleviating all fears that the new biturbo would chirp harmlessly like a budgy with a gum shield when faced with the old 6.2-litre naturally aspirated engine. Instead, the race start function now integrated into the seven=speed dual clutch transmission hurls the two-seater with the long bonnet out onto the 2.4-kilometre measurement straight. Acceleration? Oh yes, plenty! The long-stroke eight-cylinder immediately takes you aback, responding to accelerator commands practically without delay, an casually climbing to 7,000 rpm. Thus, the measuring device registers a value of 3.6 seconds for the sprint from 0 to 100 km/h, and after 11.5 seconds the 200-km/h mark is long gone.

The discreet power of the Porsche 911 Turbo

And the Porsche? Although the brand isn't really known for having the greatest restraint, the Porsche 911 Turbo is comparatively discreet - which isn't only down to the fresh coat of silver paint. Its six-cylinder turbo, which counts a pair of chargers with variable blade geometry among its special features, lets out a highly dampened, sonorous working noise. Has the boxer engine been wrapped in cotton blankets as part of daily production? However, when the 911 – likewise with the kind support of a Launch Control system – literally zooms away, that's it done with being discreet. Okay, the pair of turbines take smidgeon more time to build up to full pressure (1.25 bar), but then the car drives forward all the more extremely.

Accentuated by its unique, somehow rutting whirr, the 911 scampers from 0 to 100 km/h in a shockingly quick 3.1 seconds, and rather casually completes the sprint to 200 km/h in 10.9 seconds – a clear victory, to which the all-wheel drive with its map-controlled multi-disc clutch doesn't fail to contribute. You actually aren't aware of the working of the respective dual clutch transmission as you rush breathlessly through the seven gears, whereby the final gear, with the longer ratio, should serve mainly to increase efficiency. Both cars can now de-clutch in manual mode, and because the misleading term 'sailing' has come to be used to describe this, Mercedes shows a small ship on the central display - how nice. However, it doesn't help, as with a consumption of 12, or according to the chart: 12.6 to 13.3 l/100 km the Porsche 911 Turbo beats it here too, even if the minor difference only reduces the fuel prices by one point.

The AMG GT S with voracious handling behaviour

Just a moment – was that it regarding drive dynamics? No, the slalom and double lane-change are still to come, and the better balanced AMG (48:52 compared to 39:61 in the Porsche) is already looking forward to it. Although the low, pushed-back seating position familiar from the SLS, with the seemingly endlessly long and wide bonnet in front of it is still used, the correct rhythm is soon found, with which to drive the Mercedes-AMG GT S between the cones. Given the hefty dimensions, which are occasionally cumbersome on narrow country roads, it is surprising how boisterously the long front section corners. Handling behaviour? Pah, it is hungry for corners! Depending on the driving mode, the progressively intermeshed steering with comparatively constant power steering support is indeed always a little lighter, but is also precise, with constant feedback. In addition to this, it virtually fraternises with the aluminium double wishbone front axle, which results in practically unheard of dynamics. Added to this is the traction sticking to the road like glue, especially for a rear-wheeler in this performance class. Thus, it takes your brain a little time to come to terms with the fact that the hefty AMG GT S responds to changes of direction, tears up corners and builds centrifugal force with such agility, neutrality and stability. Until - yes until - its rear-wheeler soul breaks free and announces itself in the form of oversteer – soft, but definite,and finally the rear drive shafts find themselves alone in the choke-hold of the maximum torque of 650 Newton metres. Power oversteer? A question of honour.

However, it is no question in the Porsche, as the 911 Turbo is more of a load change kind of car, if a spectacular rather than a precise driving style is ever required. There is just no time for such nonsense as ultimately the 911 wants to top the exceptional results of the AMG GT S toppen. And in actual fact: it flies even faster through the cone formation, building up even higher cross-forces, and remains more stable – with kind regards from the co-steering rear wheels. The steering itself, equally exceptionally well tuned as that of the Mercedes, merely required slightly higher holding forces. Incidentally: the fact that the turbo bodywork is six centimetres narrower certainly won't do it any harm when playing the shell game.

Regarding the coefficient of friction...

It is still difficult to comprehend the crazily high speed that the turbo produces – and with practically any coefficient of friction. Wet conditions? Makes no difference. Here the AMG struggles. Less so on dry, warty country roads, on the other hand, where the chassis tuning AMG GT S also barely looses traction. Of course, neither of the sports cars offer cuddly suspension, but they don't have to. One difference remains: the 911 definitely deals slightly better with transverse joints and potholes. As in the Mercedes, the damper characteristics in the individual modes differ clearly from one another, even if your orthopaedist recommends that you only activate the most firmest setting on flawlessly asphalted race tracks. Incidentally, it is there that the ESP can work in the most liberal mode. While in the drive dynamics disciplines the lower speed delta with and without ESP speaks further in favour of the tuning of the Porsche – interventions are reduced due to the higher mechanical grip – the electronics of the Mercedes-AMG GT S allow sufficient sideslip angle to find the ideal line.

The 911 Turbo  is the more expensive speedster

But it doesn't help as the 911 Turbo remains the king of speed, a more sober technocrat, always striving for neutrality. However, for this sense of intimate embrace Porsche charges 30,798 Euros on top of the price of the Mercedes-AMG GT S. This spoils the 911's party somewhat, particularly seeing as the fast AMG is no less fascinating for the money. A wicked V8, a high limit range followed by oversteer – it feels like a passionate French kiss. And with a smack the suction cup of the measuring device detaches.



Hans-Dieter Seufert


22 July 2015
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