BMW to offer double-clutch autobox for 335i

BMW will soon offer drivers of the 335i Coupé and 335i Convertible the option of a new sports automatic transmission with a double clutch, a replacement for the previous 6-speed Steptronic gearbox. The new 7-speed transmission is said to permit faster acceleration than the 6-speeder manual, reduce fuel consumption and emissions and can be controlled via the gear selector or steering wheel-mounted shift paddles.

The newly-designed shift lever is clearly differentiated from a conventional automatic transmission selector lever by its shape and its integrated display for the selected shift program. There is no mechanical linkage as the driver’s inputs are communicated electronically. The shift layout is the same as that of a regular automatic transmission, though the lever always returns to its original position after performing a selection. The shift program in use or gear position is shown on the shift lever display and is repeated on the instrument panel.

The new transmission was developed for the BMW 335i Coupé and 335i Convertible and is able to handle the output of the powerful and high-revving engines fitted to these vehicles, eg 225 kW and 400 Nm of torque.



The key benefit of the new transmission is that drive torque to the rear wheels is not interrupted during the gear shifting phase as in conventional manual transmissions, meaning acceleration is constant and seamless, just like a conventional automatic. A full gear change now takes place in the time a conventional manual transmission would take merely to disengage the clutch.

In the case of the 335i Coupé fitted with the new transmission, claimed 0 to 100 km/h acceleration time is now just 5.4 seconds – 0.1 second quicker than the model fitted as standard with a 6-speed manual transmission, and 0.3 seconds faster than the 335i Coupé with the previously available 6-speed automatic transmission.

Enthusiastic acceleration goes hand in hand with outstanding shift comfort especially in day-to-day stop-start traffic. The swift, slick change of gears makes for sublime acceleration. The load change reactions associated with conventional transmission systems are completely eliminated. Even when accessing the maximum dynamic performance available, a level of comfort is achieved, which was not feasible previously, says BMW.