Porsche Doppelkupplungsgetriebe (PDK)
The new generation 911 Carrera 4 and 4S are available for the first time with the new Porsche Doppelkupplungsgetriebe (PDK), literally Porsche double-clutch gearbox. Offering no less than seven forward gears, the new gearbox combines the driving comfort of a torque converter- equipped automatic transmission with the dynamic manual gearshift functionality of a sequential racing gearbox. PDK also boasts an entirely automatic gearshift function, and replaces the Porsche Tiptronic S automatic transmission previously offered. Through its optimised and adaptive gearshift programmes, PDK further improves the acceleration of the 911 and reduces fuel consumption to an even lower level.
In principle, the PDK consists of a conventional manual gearbox and a hydraulic control system divided into two separate transmission units. Two wet clutches in radial arrangement, controlled hydraulically, and using oil for both cooling and lubrication, form the heart of the transmission. One clutch is for the first transmission unit with the uneven gear ratios (1,3,5,7) and reverse, and the other clutch is for the second transmission unit with the even gears (2,4,6). Via a number of pressure valves, the hydraulic control unit masterminds both the wet clutches and the shift cylinders activating the transmission ratio required.
The gearshift perceived by the driver comes not from the gears actually changing, but from the change of positive clutch engagement. In this case, the clutch on one transmission opens or disengages while the clutch on the other transmission closes or engages in a simultaneous process. The big advantage is an even faster gearshift than with a conventional manual gearbox or torque converter automatic transmission. The gears are already ‘in mesh’ when shifting and the power of the engine need not be interrupted in the process.
PDK also reduces to a minimum transmission power loss courtesy of the high standard of mechanical efficiency in the double-clutch, and this manifests itself in fuel economy improvements of approximately 13 per cent compared with a conventional Tiptronic S transmission. PDK also offers an advantage in terms of weight – despite two additional gears, it weighs 10kg less than Tiptronic S.
To use the various functions of the double-clutch transmission, the driver can either shift gears by means of sliding toggles on the spokes of the new steering wheel, or via the new gear selector lever. The driver can press forwards to shift the gears up, and press them from behind to shift downwards. Alternatively, pushing the gear selector lever forwards shifts up a gear, and pulling it back shifts down. The option of PDK costs £2,338.
This PDK gearshift principle was first developed by Porsche for motor sport 25 years ago. Porsche works drivers benefiting from this technology were able to accelerate faster than their competitors and keep both hands on the steering wheel while changing gears, thus avoiding even the slightest distraction while shifting.
The seven-speed PDK shifts gears up to 60 per cent faster than a conventional automatic transmission, and naturally, gives the new 911 Carrera models even better performance. And those in search of optimum driving dynamics have the option to combine PDK with Sport Chrono Package Plus, now featuring Launch Control.
As with the two-wheel drive 911 Carrera models, the new generation of the Carrera 4 is evident through the discreet modification of the nose and tail and its use of new lighting technology. All Carrera models feature, as standard, bi-xenon headlights and new LED daytime driving lights. Dynamic Cornering Lights are available as an option.
The 911 Carrera 4 models are 44mm, or 1.73”, wider across the rear wheel arches than the two-wheel drive versions. Further definition and character is added courtesy of a new reflective trim that spans the width between the LED rear lights.
Porsche Communication Management (PCM)
Inside the 911, the new Porsche Communication Management (PCM) centre console with its larger, touch-sensitive screen improves operation of the audio system and optional satellite navigation to an even higher standard. And a further important point is that PCM is now compatible with Bluetooth, USB and iPod requirements.
The second generation Porsche 911 Carrera 4 models go on sale in Great Britain and Ireland on October 25. The Carrera 4 Coupe 3.6-litre is priced from £67,430, and the Carrera 4S Coupe 3.8-litre is priced from £74,720. The 911 Carrera 4 Cabriolet is priced from £74,720, and the Carrera Cabriolet 4S from £82,010.
Fitted to every 911 is a Porsche Vehicle Tracking System (VTS), a sophisticated vehicle security package approved to Thatcham Category 5 standard, and owners will also be able to explore the potential of their new car on a Porsche Driving Experience course.