Mid-week long read: shifting perspective
There is a long-held belief that a proper sports car needs a manual gearbox. That the purist’s Porsche is always the one with a stick. But past and present beg to differ. The first two-pedal 911 appeared over 50 years ago and the incredible recent advances in our dual-clutch transmission have made PDK the performance default today.
The uproar was considerable back in 1967, when Porsche first offered the 911 with its semi-auto ‘Sportomatic’ ¬transmission. And it wasn’t just dyed-in-the-wool purists who were dismayed; the world’s media was equally sceptical. The omission of a clutch pedal was designed to increase the sense of luxury and comfort. Comfort? In a sports car? On top of that, the system was two seconds slower to 100 km/h than the traditional manual and fuel consumption was actually higher. Despite some high-profile sporting success in a 911 R driven by none other than ‘Quick Vic’ Elford, the Sportomatic failed to find a foothold.
Fast-forward half a century and the racing landscape has changed to such an extent that manual gearboxes are a distant memory. And the technology transfer that Porsche has always sworn by, taking its latest advances from racetrack to road, means there is now a universal acceptance that PDK delivers what a traditional shifter can’t.
In fact, more than three-quarters of all 718s and 911s built today are ordered with PDK. And while ease of use is the primary driver for many customers, maximising a car’s potential is still a key part of Porsche’s mission. For flagship models like the 911 GT3 RS, the PDK transmission that comes as standard has been fine-tuned with shorter gear ratios, optimally stepped gears, and faster response times. PDK was created to go racing after all.
Initial trials of the new technology started in 1980, and just three years later Porsche was fitting the famous 956 Group C racers with the system and pitting it against the massive demands of endurance racing in the World Sports Car Championship.
But what were our engineers hoping to achieve? In a PDK ‘box, the gears are distributed between two separate clutches. The odd gears and reverse are connected to the first clutch, while the even gears are connected to the second. Similar to a manual shifter, the individual gears are selected using shift forks, but in the PDK system, it’s done through computer-aided electrohydraulics. The result is a synthesis of manual and automatic shifting, both faster and smoother. The system’s significant advantage, particularly in combination with turbo engines is that, unlike with a manual transmission, drivers can keep their foot on the throttle during gear changes, and the charge pressure of the turbo is retained. This means there is no interruption to the car’s traction, providing small but hugely telling gains on the circuit.
Despite promising results in racing, there would be a considerable delay before PDK was deemed refined enough appear in our road cars. The control electronics had to go through a number of developmental stages, primarily to smooth out the shifts for daily use. But starting in 2008, Porsche offered an optional seven-speed PDK in the 911 Carrera and the 911 Carrera S, and a year later the new Panamera became the first Porsche with a standard seven-speed PDK. And in a significant move for our GT Department, the 2013 911 GT3 was introduced exclusively with the next gen PDK II.
The purists were up in arms again, but even the first generation of the PDK enabled faster gear changes, up to 60 per cent faster and without traction interruption. That naturally impacted acceleration. The 2008 Porsche 911 Carrera with a seven-speed PDK — in Sport Plus Mode — shifted 0.4 seconds faster than the equivalent car with a manual six-speed transmission, bringing the 0-100 km/h time below five seconds for the first time.
But all this was never exclusively about performance. The PDK’s positive impact on fuel consumption was immediately evident in 2008: with a six-speed manual transmission, a stock 911 Carrera S consumed 10.6l/100km ¬— 0.4 litres more than with PDK. And today, when it matters more than ever, the new standard eight-speed box, is even more efficient, changing gear in milliseconds for significant gains on all fronts.
Devotees of a physical shift will never be overlooked at Porsche, of course. The latest 911 GT3 and Speedster are offered with a unique six-speed manual, and the recently released 718 Cayman GT4 and Spyder, uncompromising driver’s cars both, are only available with a three-pedal set up. The next model year will also see the arrival of a seven-speed manual option in our 911 Carrera series, but it is PDK that has become the technological lodestar, a powerful force for both performance and efficiency, and an essential part of Porsche’s onward journey.
718 Boxster GTS: Fuel consumption combined 9.0 – 8.2 l/100 km; CO2 emissions 205 – 186 g/km
991.1 GT3: Fuel consumption urban 18.9 l/100 km; extra-urban 8.9 l/100 km; combined 12.4 l/100 km; CO2 emissions 289 g/km; efficiency class (Germany): G
Panamera GTS: Fuel consumption combined 10.3 l/100 km; CO2 emissions combined 235 g/km