2009 911’s PDK dual-clutch improves Nurburgring lap time
Porsche took its new three different 911s to Nürburgring for a comparison. And featuring the new twin-clutch automated manual Porsche Doppelkupplung (PDK) transmission, PASM (Porsche Active Suspension Management) Sport, and "sports tires," the new 2009 911 Carrera S had a lap time of 7:50.
Next was the 2009 Porsche 911 Carrera S (presumably with manual transmission) with a time of 7:58 and last the current 911 Carrera S with 8:02.
According to the company the PDK shifts 60 percent faster than the former Tiptronic S automatic, and offers a small improvement in fuel economy over the six-speed manual-equipped 911.
Source: Inside Line