Audi's new S-Tronic: 7 gears for fun and profit

With fuel-saving potential and Shumaker-speed shifting, Audi's S-Tronic gearbox is one of the most entertaining features ever fitted to an automobile. Not leaving well enough alone, Audi engineers have been tinkering, and the transmission is about to get better.

Suitable for longitudinal installation and all wheel drive, Audi says the new breed of S-Tronic gearboxes will have one crucial addition- a seventh gear. Among other benefits, the seventh gear can allow the engine to remain in its power-curve for more of the time, while allowing lower highway-speed revs, resulting in a reduced fuel bill.



Actual gear-cogs are mounted in a straight line to a pair of shafts, while a pair of multi-disc clutches select which cog is active at any time. With any gear engaged, the following gear is always pre-engaged, or 'lying in wait' so to speak. Switching between the two gears takes just a few hundredths of a second and poses no interruption in traction. The engine control module adjusts the RPM's instantly to match the requested gear as well, so drivers hear the gearchanges but won't feel them.

Gears can be switched automatically by leaving the selector in "Drive", while a sportier automatic shifting pattern is available in the "Sport" setting. Manual gearshifts are available with steering-wheel mounted shift-paddles, or by tapping the gear-lever up or down.

Competitors Mercedes-Benz and BMW have been using seven-speed transmissions for several years, while Lexus even has an eight-speed automatic in production. The new seven-speed S-Tronic gearbox will be fitted to selected models later this year.