Which is Wet and Which is Dry Between 6-Speed Dual Clutch and 7-Speed Dual Clutch?
2 Answers
6-speed dual clutch is wet and 7-speed dual clutch is dry. Here are the specific introductions: 1. Wet dual clutch: Wet dual clutch refers to a multi-plate clutch system where two sets of clutches, one large and one small, are coaxially installed together in a sealed oil chamber filled with hydraulic oil. Therefore, the wet clutch structure has better adjustment capability and excellent heat dissipation, enabling it to transmit larger torque. Due to layout and friction material selection factors, the size of a wet dual clutch is larger than that of a dry dual clutch, which is not conducive to the arrangement of the vehicle's powertrain. 2. Dry dual clutch: The working principle is that the dual clutch consists of three similarly sized clutch plates coaxially stacked together. The two outer clutch plates are connected to gears 1, 3, 5, 7 and 2, 4, 6, reverse respectively, while the middle plate moves between them, engaging or disengaging with the two clutch plates to shift gears.
A few days ago, I disassembled the transmission to study this issue. Both 6-speed and 7-speed dual-clutch transmissions come in dry and wet versions—you can’t just judge based on the number of gears. For example, the commonly used 7-speed DQ200 dual-clutch transmission from the Volkswagen Group is a dry design, relying on air cooling for its simple structure and fuel efficiency, but it’s prone to overheating in city traffic jams. Meanwhile, the 7-speed DL382 often used in Audi is a wet type, submerged in oil for cooling, making it more durable. The same logic applies to 6-speed transmissions: the older Golf GTI’s 6-speed DQ250 is wet, while some domestic cars use a dry 6-speed. When choosing a car, you need to look at the specific model—small-displacement cars often use dry types, while those focused on sporty performance mostly come with wet ones. Don’t be fooled by the number of gears; focus on the usage scenario and the manufacturer’s tuning.
