The Direct-Shift Gearbox (Direktschaltgetriebe) is a dual-clutch gearbox designed by BorgWarner and initially licenced to Volkswagen Group (which owns the Volkswagen, Audi, SEAT, Bentley, Bugatti, Lamborghini, and Škoda brands). By using two clutches, fast shifts can be achieved, and the torque converter of a regular automatic transmission is eliminated.
Essentially, the engine drives both clutch packs. The outer clutch pack drives gears 1, 3, and 5 (and reverse). The inner clutch pack drives gears 2, 4, and 6. Instead of a standard large dry clutch, each clutch pack is a collection of four small wet interleaved clutch plates, due to space constraints, one clutch assembly is concentric to the other. Because the alternate clutch pack’s gearing can be pre-selected, ’shifts’ are eliminated and the gearshifts become gear transitions. The DSG takes about 8 milliseconds to upshift. Compare that to the SMT in the Ferrari Enzo, which takes 150 ms to upshift. The quoted time for upshifts is only the time the engine is completed non-powered.
VW group vehicles available in Europe with the DSG gearbox include:
Audi TT and A3. Audi have named the DSG "S-Tronic" in newer models.
Bugatti Veyron 16.4 (* not a Borg Warner DSG, but marketed as one due to parent company)
SEAT Altea, Toledo, and León
Škoda Octavia
Volkswagen Passat, Golf/GTI, Touran, Eos, Jetta/Bora, and Golf_R32