Porsche 991 Carrera S Road Test: what else ?

We take the wheel of THE new GT of the year : the type 991 version of the Porsche 911 Carrera S.

When Porsche undertook to define the 991 platform, three fairies congregated around the cradle: the designers, guardians of the temple, the chassis engineers and the motorsports department. The chassis and racing fairies were adamant that a sizable increase in wheelbase was a must. In the ensuing horse trading, the style fairy ended up agreeing on 100 millimeters, confident that she could still pursue her endeavor: to conjugate tradition and modernity on a 50 year old canvas.

The scene is set in a large city, somewhere in the world. A pedestrian spots a familiar shape in traffic, a pair of circular headlights. In an instant, current flows through synapses. It’s a Porsche, a 911, no doubt. The gaze follows the silhouette as it drives by.  The horizontal line connecting front and rear fenders, the characteristic C pillar contour. A fifty years old trademark in automotive design. Now comes the rear. Sharper, squinting tail lights linked with a straight undercut. Without a doubt, it is a new 911, thenew 911. This narrative – easily transposed on a freeway – imaginary but so plausible, sums up the design brief. Unequivocal recognition of brand and model, clear differentiation from the outgoing car.

Seen in isolation, the new car sticks to this storyboard to a surprising extremity. Walking towards the front of the car, it is easy to mistake the 991 for a 997, while the rear is more boldly designed with tense horizontal lines. It is when you compare the two cars side-by-side that differences hit. The wheelbase of the 997 now appears comically short, the roofline bulbous, its nose long and pointy. The 991 appears wider, longer and taller, while it really isn’t. The rear wheels are now 100mm (4 inches and change) more distant from the front to reach 2450mm, but the overall length has grown by 56mm only. Front overhang is shorter, the boot cover has gained curvature. The waist line is considerably higher while the roofline has sunk by 5mm, shrinking the glass surfaces. Driving elbow out requires unnatural stretching of the elbow and wrist joints, a good way to shake out a bad habit.

On the front facia, clues are subtle. The V lines of the 997 mk2, drawn from the headlamps down to the radiator vents are now trapezoidal to give the car a broader visual stance. The easiest change to spot is the mirrors, which have migrated from the A pillar base to the crest of the doors. The longer wheelbase is designed to benefit taller drivers with 20mm extra in adjustment length and 10mm more in steering column reach (now electric), the space left to rear passengers remains very tight. Seating an adult, even for a short distance, remains an unrealistic or sadistic undertaking. The 911 remains a strict 2+2, sparse for passengers but generous for luggage.

Interior design has taken a leap, drawing from the best of the corporate portfolio, foremost the raised central console inaugurated on the Carrera GT, democratized on the Panamera and then on the new Cayenne. It is much narrower though, pushing (too far) behind the gear lever essential switches. Suspension, exhaust and powertrain management toggles should not require to take ones sight so far away from the road, further more as there’s no permanent indicator in the instrument cluster. The 7 inch tactile screen displays one of the best vehicle interfaces of contemporary automotive production, with complements coming courtesy of an auxiliary LCD lodged at the far left of the traditional pentacle. Design and material selection and finish progresses and remains, with Audi, an undisputed reference.

Beside wheelbase, another crucial chassis dimension has evolved radically: Porsche increased the front track by no less than 52mm while the rear track remains unchanged. The result is a game changer, perhaps one of the most fundamental changes in modern history of the 911. Front grip is increased dramatically and far less sensitive to weight balance and throttle position. Back to back comparison with a 997.2 Carrera S is more than a revelation, it’s a shock. On the same fast sweepers in the west Switzerland back country, part dry, part damp, the 991 inspires confidence where the 997 demands restraint. Reactions to throttle modulation are far more subtle and contained. Stark understeer when powering out from a mid corner apex is nearly a thing of the past. The front wheels carve the asphalt, faithfully hooked into imaginary tracks drawn by the driver’s eyes, this 911 does without the bizarre tricks that were necessary to tame older generations. The contrast is obvious, fundamental, the outcome exhilarating. Stepping out of the track, giving credit to Porsche’s claims that the 991 Carrera S is as fast on the Nordschleife as the outgoing 997 GT3 is not difficult. We were not able to isolate the contribution of the PDCC (Porsche Dynamic Chassis Control), fitted on our test car and whose actuators actively fight body roll.

Zuffenhausen’s acoustic engineers spared no efforts on the 991. The Carrera is fitted standard with a new system called Sound Symposer, a passive system which picks up acoustic waves from the intake port and routes them to the cabin, using the rear window shelf as a loudspeaker. The system is active in Sport and Sport Plus modes. Our test car was also equipped with the Porsche Sport Exhaust (PSE) system. Here also, it is difficult to tell the contribution of one system from the other, but the combination gave our test car a very attractive exhaust note, distinctive from prior models in being more subtle and less raspy. The ensemble plays a very pleasing partition above 2800 rpm, but less so below where harmonics seem to be drowned in viscous sludge. One more reason to keep the tacho well above 3000 rpm and enjoy the melody ! On overrun, the exhaust burbles nicely, too nicely not to be carefully engineered. More than ever, the prospective buyer will be well advised to test a PSE-equipped car before signing off the car specs.

Porsche claims 1415kg DIN (i.e. with a 90% full tank) for a PDK equipped Carrera S. We measured our test car at 1518kg, with 38.3% on the front wheels and 61.7% on the rear. German magazine Sport Auto measured their 991 Carrera S PDK at 1497kg (38.1%/61.9%) on a car with the PCCB carbon ceramic brakes and no sunroof. We also put a Porsche 997.2 Carrera S on our scales and saw 1473kg with the same 3.8L direct injection engine but a 6 speed manual gearbox. We are therefore unable to confirm that the 991 is lighter than the 997, further less the rather surprising figures listed on spec sheets.

The new PDK gearbox is now sitting at the pinnacle of double-clutch robotized gearboxes, thanks to notable progress in critical areas. Schlepping in traffic, it now stands out in terms of smoothness, agility and precision. Porsche engineering, who is said to have taken over firmware development from their supplier, have also significantly improved shifts at the sportier end of the driving business. The artificial jerks induced by the 997.2 PDK box software are gone. In Sport Plus mode, deep in the power curve, shifts are crisp, clean, with just the right amount of mechanical harshness to reflect a process that should somehow be a little brutal. Downshifts are splendid, with revs exquisitely matched. The paddles of the optional Sport Design wheel are a mandatory – albeit costly – upgrade to the standard push-pull system Porsche stubbornly fits as standard. Compared to the absolute reference in sports car gearboxes, the Ferrari 458 Italia, still falls short of the Italian alchemy that, at full tilt, melts tactile and mechanical feel to procure the ultimate experience in gear changes, but the PDK system scores points for compliance in mundane situations. We have not been able yet to sample the manual 7 ratio stickshift, it could be a rare sight.

Under the rear bonnet, the biggest change is the disappearance of … the engine. Porsche chose to increase body stiffness by drawing a narrower opening. Hidden underneath, the flat 6 of the Carrera has shrunk from 3.6 to 3.4 liters, but the Carrera S maintains displacement at 3.8L. Porsche squeezed 15 hp through higher revs (400 at 7400 vs. 385 at 6500 rpm on the 997.2 Carrera S). Torque progresses by 20 Nm (14.7 lbft) at 440 Nm, but peaks now at 5600 rpm, or 1200 rpm higher than before. With all disclaimers owed to a brand new engine with a couple hundred miles under the belt, the difference does not appear substantial, furthermore as, final drive ratio being equal to the 997, the 991 pulls longer due to is the larger 20in wheels. The new engine feels more lively above 4500 rpm, but we’ll have to wait for a fully broken in engine to pass judgment.

Porsche has blessed the 991 of the latest innovations from its Porsche Intelligent Performance efforts through a flurry of systems and features aimed at improving mileage and reducing emissions. Efforts that also come down to Intelligent Finance due to the carbon dioxide penalties imposed throughout Europe on vehicles exceeding 130 g/km. One such innovation is the adoption of electric steering assistance instead of a conventional hydraulic system. Many enthusiasts may have frowned when learning about this change in launch press coverage, and it turns out that they were right. Steering feel is bland and of little substance. Weighting is a little too light, ratio not direct enough, and it has become more difficult to stay connected with grip conditions under the front wheels. I remember vividly a 70 degrees turn on a climb through country roads, approached with a little too much optimism. It’s the perception of a widening line than the feedback at turn in that enticed me to partially lift to complete the corner safely. Engineering such a filter between a brilliant chassis and steering wheel is a pity. A saving of 0.1 L/100km could hardly be worth it.

Another innovation is the coasting function. In normal mode, the PDK gearbox opens the clutch when it detects a situation where free inertia is the most economical way to maintain momentum. The car then glides forward, engine idling, preserving momentum rather than feeding the engine to prevent engine breaking.  On fluid but busy freeways, the most noticeable side effect is to have the orange rev needle oscillating in the peripheral field of vision between 1800 and 800 rpm as the system engages and disengages. Things get far more annoying in certain city driving situations, for instance when approaching a round about, when the system clutches while you were counting on engine breaking to adapt your speed just so. Fortunately, the system is not active in manual mode, or in sport/sport plus modes. A stop-start system is also part of standard equipment and does a decent job, even if the flat 6 feels sometimes slightly slow to resume service. A compromise for a theoretical 0.6 L/100km and another few grams of precious CO2 savings. Seventh gear is extremely tall, pulling 2400 rpm at 150 km/h (93mph), adequate for cruising but hopeless should you want to accelerate to extract yourself from traffic. We measured 14.3 L/100km of fuel consumption (14.0 displayed on the on board computer), a figure to put in perspective with a brand new engine and the resulting added friction.

For 100mm in length and 52mm in width, the 991 Carrera is the 911 it should always have been. It preserves its core strength, but adds a crucial new selling point: far superior – and more conventional – handling. The best of both worlds: a rear engine layout providing unmatched interior space and traction, but without the cornering idiosyncrasies that used to be so particular to Porsche’s flagship product. The 991 comes out of this test as a stellar success, a model that will only reinforce its benchmark status in the GT segment. Porsche 911: what else ?

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* 997.2 Carrera S with manual gearbox and sport seats **4.1s with Sport Plus & PDK ***13.6s with Sport Plus & PDK

Our sincere thanks to the Centre Porsche Genève Centre Porsche Geneva team for the loan of their 991 Carrera S demo car.

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