S tronic, the Audi revolutionary direct shift gearbox (formerly DSG) combines the advantages of a conventional six-speed manual-shift gearbox with the qualities possessed by a modern automatic transmission. The driver enjoys immense agility and driving pleasure with, at the same time, smooth, dynamic acceleration with no interruption to the power flow.
The technical basis of the S tronic is a double clutch. This consists of two wet plate-type clutches with hydraulically regulated contact pressure. One of the two clutches engages the odd-numbered, the other the even-numbered gears. This principle enables gear shifts to be made without interrupting the power flow and keeps the shift times extremely short. While the first clutch is transmitting the power, the second clutch is ready to engage the next gear, which is preselected. When the driver makes the gear shift, the first clutch is released and the second engages, so that the gear shift takes place in a fraction of a second.
The driver can operate the S tronic manually or allow changes to take place automatically. In the automatic mode there is a choice between the well-balanced, comfortable standard shift settings and a program with greater sports emphasis. Manual shifts are made either at the gear lever or at shift paddles behind the steering wheel.