DSG is Direct Shift Abbreviation for Gearbox，Direct shift gearbox，That is, the dual-clutch gearbox widely used by Volkswagen。Actual test data shows that Volkswagen DSG gearbox has better shifting comfort and fuel economy than other types of gearboxes。

The gearbox serves as the bridge between the engine and the wheels，SeabetCan be based on vehicle speed and load requirements，Through automatic gear shifting, the engine's power is automatically converted into reasonable torque and speed of the wheels。Dual-clutch gearboxes are available in wet and dry types，The main difference between dry type and wet type is the way the engine transmits power to the clutch of the gearbox。

Dry clutch gearbox is an automatic gearbox clutch that transmits power through dry friction，The clutch pressing plate and driven friction plate of the wet clutch transmission are in the oil，That is, relying on oil to control the Seabetengagement and separation of the clutch，Thus achieving the function of power transmission。

(Wet clutch cross-section)

In addition to the main differences above，Wet dual-clutch gearbox has one more intermediate shaft than dry dual-clutch gearbox，This way，Wet dual-clutch gearbox can be matched with the engine to form a front-wheel drive configuration，Can also drive the front wheels at the same time、Rear wheel，A four-wheel drive configuration is formed。

Due to the above structural differences，Dry and wet dual-clutch gearboxes also have their own characteristics，For example:

1. Shift speed。Dry clutch is driven by direct contact with metal sheets，More direct power transmission，The metal piece is pressed tightly，Transmission ratio increased，The effect is immediate and significant；The wet clutch plate relies on oil to control the Seabetengagement and separation of the pressing plate and the driven friction plate，The time for oil pressure to build up is longer than the time for dry clutch to directly contact to transmit power，So，The response speed will be a little slower。

2. Fuel consumption economy。Due to the viscosity of the oil film between the friction plates of the wet clutch，So that the friction plates cannot be 100% separated，Loss of part of the transmission efficiency，The power transmission efficiency is not as high as that of dry type。

3. Torque bearing capacity。The metal friction plate of the dry clutch itself is not as capable of withstanding torque as the wet torque converter，And the heat generated by metal friction is mainly dissipated by air movement，The heat dissipation performance is not as good as wet oil movement heat dissipation，The above reasons lead to the torque tolerance of dry clutch not being as strong as wet clutch。Therefore, dry clutches are mainly used for vehicles with small displacement and low torque output。