BMW introduces its new sports automatic transmission with double clutch
BMW will offer drivers of the 335i Coupé and 335i Convertible the option of a new sports automatic transmission before the end of the year.
The new sports automatic transmission with double clutch, offered in addition to the standard six-speed manual, replaces the previous optional 6-speed Steptronic gearbox. The new 7-speed transmission delivers faster acceleration than the 6-speed manual, reduces fuel consumption and emissions and can be controlled via the gear selector or steering wheel-mounted shift paddles.
Which ever shift method is chosen, the 7-speed double clutch transmission shifts without interrupting the drive from the engine to the rear axle, enhancing acceleration and shifting comfort.
The newly designed shift lever located in the central console is clearly differentiated from a conventional automatic transmission selector lever by its shape and its integrated display for the selected shift program. It controls the gearbox electronically, there is no mechanical connection.
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, for example 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 BMW 335i Coupé fitted with the new sports automatic transmission, the zero to 100 km/h acceleration time is now just 5.4 seconds – 0.1 seconds faster than the model fitted as standard with a 6-speed manual transmission, and 0.3 seconds faster than the BMW 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.
The BMW 335i Coupé fitted with the new 7-speed sports automatic transmission with double clutch achieves average fuel consumption in the EU test cycle of 9.1 litres per 100 km. This represents a reduction of 0.4 litres per 100 km over the 6-speed manual or previous 6-speed automatic transmission.
The average fuel consumption of the BMW 335i Convertible with the new 7-speed sports automatic transmission is 9.1 litres per 100 km. This is equivalent to a reduction in fuel consumption of 0.8 litres compared to the equivalent models with 6-speed manual and 6-speed automatic transmissions.
When combined with the top-of-the-range twin turbo 335i engine, the sports automatic transmission with double clutch offers driving dynamics previously only provided by high-performance sports cars.
The new optional sports automatic transmission with double clutch will be available in the BMW 335i Coupé and Convertible from December 2008, priced at $3,500.