Benjamin M. Monroe Blog: MINI models F56, F57 and F55 get a new transmission: 7-speed dual-clutch

Monday, December 18, 2017

MINI models F56, F57 and F55 get a new transmission: 7-speed dual-clutch

Even before their facelift, the small MINI models F56, F57 and F55 will receive a new transmission: A 7-speed DCT will replace the previously offered six-speed automatic transmission in MINI One and MINI Cooper D, and should provide noticeable efficiency benefits. Together with the dual-clutch gearbox, a new gear selector lever is moving in, which looks more modern and sportier than the previous version.

The 7-speed DKG allows gear changes without interrupting the traction effort, because two partial transmissions are paired in a common housing. Two oil-cooled wet clutches are the core of the system and connect the two partial transmissions. With a gear change under load, a simultaneous opening of the one and closing the other clutch allows extremely fast switching operations without interruption of traction. Thus, the usual at slower gear changes load change reactions remain off. It goes without saying that the driver can select the characteristic of the transmission and thus also the gear change via the selector lever – from the usual driving in mode D to sporty driving in mode S up to manual gear changes in mode M.

Just like in many other models of the BMW Group, the shifting strategy of the 7-speed DKG also includes navigation data from MINI Connected. If the vehicle approaches a sharp bend or intersection, the transmission is informed early on and can already engage in a lower gear to take advantage of the engine drag torque for the upcoming deceleration. In sporty driving on winding roads, unnecessary gear changes are avoided to make an additional gear change in the expected acceleration.

When driving slowly in city traffic, as well as when parking and maneuvering, the MINI-DCT changes into a comfortable creep function, which facilitates smooth starting. In the lower-rev range, a dual-mass flywheel with integrated centrifugal pendulum increases the vibration and acoustic comfort.

Thanks to the car start / stop function, sailing function and, of course, the seventh gear, the DCT also contributes to the fact that the MINI One and MINI Cooper D consume noticeably less fuel than in combination with the previously used six-speed automatic transmission – whether as a three-door, five-door or convertible.