The dual-clutch transmission is an automated transmission that can change gears faster than any other geared transmission.These transmissions are equipped with different types of clutch. The gearboxes designed for low torque values feature two dry clutches while the units designed for higher torque values are equipped with wet clutches running in a sump.
source/image(PrtSc): Learn Engineering
DCTs (DSG) technology has gained a substantial market share in the recent times ( up from 3.4% to 8.5% market share in the last 5 years). This video illustrates with the help of animation why DCTs are the best transmission ever. This video also gives a brief introduction on working and drawbacks of a regular manual transmission.
The DSG automates two separate “manual” gearboxes (and clutches) contained within one housing and working as one unit.When you start driving, the half-gearbox 1 is engaged in first, while half-gearbox 2 is already in second.
You accelerate in first gear, and when it comes time comes to shift into second, clutch two intervenes to switch gearboxes. The clutch of the transmission 1 is released, and 2 is connected all at the same time. That’s the advantage of this transmission switching is fast and smooth.