BMW has announced the debut by year’s end of its new Sports Automatic Transmission with Double Clutch (quite a mouthful and no-doubt quite a gearbox) in its 335i Coupé and 335i Convertible models.

Replacing the previous optional six-speed Steptronic gearbox, the new Double Clutch transmission features seven-speeds and takes its place as an option, alongside the standard six-speed manual transmission.

The new seven-speed transmission delivers a number of benefits. A 335i fitted with the seven-speed will accelerate faster than the six-speed manual, and, while doing so, use less fuel and produce less emissions. It’s healthy for the hip pocket, the Earth and most importantly, your ego.

Gearshifts can be controlled via the gear selector or steering wheel-mounted shift paddles. Whichever shift method is chosen, the seven-speed double clutch transmission shifts without interrupting the drive from the engine to the rear axle, hence the improvements in efficiency and performance.

There is a newly designed shift lever located in the central console, which features an integrated display for the selected shift program. The shift lever controls the gearbox functions electronically, there is no direct connection between the transmission and the shifter.

Keeping it familiar, BMW have retained a shift layout that 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 with the 335i Coupé and 335i Convertible in mind and is designed to deal with the 225kW and 400Nms, developed by the sweet six-pack.

So, how quick are the gear changes? BMW is telling us that the seven-Speed dual-clutch box, can effect a gear change in the time a conventional manual transmission would take merely to disengage the clutch.

Those lightning changes help a dual-clutch equipped 335i Coupé belt from zero to 100 km/h in 5.4 seconds – 0.1 seconds faster than the same car fitted with a six-speed manual, and 0.3 seconds faster than the BMW 335i Coupé, with the previously available six-speed automatic. The same car will average 9.1 L/100km combined cycle, a reduction of 0.4 L/100km over the manual and previous auto equipped variants.

The new optional sports automatic transmission with double clutch will be available in the BMW 335i Coupé and Convertible from December 2008, priced at $3500.