Porsche Doppelkupplung (PDK), with both manual and automatic modes, enables very smooth gear changes with no interruption in the flow of power. This results in more responsive driving combined with reduced fuel consumption and emissions. In conjunction with direct fuel injection (DFI), depending on the model, fuel consumption can be reduced by as much as 15 % and CO2 emissions by as much as 16 % (when compared with the corresponding previous model).*
PDK is essentially two half gearboxes integrated into one housing and thus requires two clutches. This double clutch provides an alternating non-positive connection between the gearbox and the engine via two separate input shafts (input shaft 1 is nested inside the hollowed-out input shaft 2).
The flow of power from the engine is only ever transmitted via one part gearbox and one clutch, while the next gear is preselected by the second clutch. During a gear change, a conventional shift no longer takes place. Instead, one clutch simply opens and the other closes at the same time. Gear changes therefore take place within a few hundredths of a second.
The excellent efficiency and the long-ratioed 7th gear help to achieve reduced fuel consumption and emission figures when compared with a manual transmission. In essence, PDK combines sportiness with efficiency and comfort: typically Porsche.
* The fuel consumption saving given is determined from the figures in the NEDC (New European Driving Cycle). For model year 08 to Euro 4 (80/1268/EEC), for model year 09 to Euro 5 (715/2007/EC and 692/2008/EC). The figures do not relate to an individual vehicle but are intended solely as a means of comparing different vehicle types.