The 7-speed S tronic dual-clutch gearbox represents the most advanced technology of dual-clutch gearbox at present. It consists of two transmission shafts and two groups of multi-disc clutches, which control different gears respectively. When one clutch controls the connection between the transmission shaft and the engine, the other system is on standby at any time. For example, when the driver accelerates in the third gear, the other transmission shaft is ready for the fourth gear, and the shift is realized by changing the clutch. It takes only a few hundredths of a second to complete the shift quickly and smoothly, thus minimizing the power loss during the shift.
The 7-speed S tronic dual clutch gearbox has fully automatic modes, including D (standard) mode and S (sport) mode. There are two switching modes for the driver to choose from-through the shift lever or through the shift paddle behind the steering wheel. In addition to the 7-speed S tronic dual-clutch gearbox for vertical engines, Audi also has two other S tronic gearboxes for horizontal engines, which adopt 7-speed and 6-speed structures respectively.