How it works
Two independent gearbox units make up the DSG. With dual-clutch technology – two clutches in a common housing – either gearbox is able to connect under load to the engine, depending on the current gear, via two drive shafts. Clutch 1 serves the first gearbox unit with 1st, 3rd, 5th, and reverse, while clutch 2 serves the second gearbox unit with 2nd, 4th, and 6th gear. An output shaftthat applies the torque to the driven wheels via the differential gear is assigned to each gearbox unit.
Thanks to the dual-clutch design, the DSG system is more efficient than a conventional automatic transmission. While a torque converter is engaged at all times (increasing load and fuel consumption of the engine), the DSG gradually opens the clutch, allowing the engine to idle freely. In most cases, this efficiency with its low weight and intelligent control means that DSG can achieve the same or better fuel consumption than even a manual gearbox.¹
Mechatronics – electronics and mechanics in one unit
Clutches and gearbox units area operated hydraulically by the gearbox mechatronics (a combination of mechanics and electronics) housed in the DSG. The electronic transmission control unit, sensors, and hydraulic control form one compact unit.
The control unit does the thinking for you, using information such as engine speed, road speed, accelerator position, and driving mode to select the optimum gear and to determine the ideal shift point. The hydraulic control unit then implements the shift command in a sequence of precisely coordinated actions. The change of gear is imperceptible to the driver, who is merely conscious of the uninterrupted power.