The purpose of the double-clutch technique is to aid in matching the rotational speed of the input shaft being driven by the engine to the rotational speed of the gear the driver wishes to select. ... When the speeds are matched, the gear will engage smoothly and no clutch is required.

Why is dual-clutch faster?

When compared to manual transmissions and traditional automatics, dual-clutch automatics are quicker to shift. The powertrain never has to be disconnected from the transmission, which allows for lightning-quick gear changes. The result is improved acceleration compared to a traditional manual or a regular automatic.

Does double clutching make your car faster?

This is because the process involves matching the engine speed with the gear you want to change into - but as you can only directly affect an engines speed when it isn't in gear by increasing it (using the accelerator), double clutching isn't used for accelerating as you would need to drop the engines speed relative to ...