In the fierce competition between luxury automakers, every detail is a potential battlefield, including the number of forward ratios in an automatic transmission. Mercedes-Benz struck first with its seven-speed automatic, which prompted eight-speed responses from Lexus, along with BMW, Audi and even Hyundai. These slushboxes are packed with technology and can either rifle off extremely fast up- and downshifts or coddle their occupants with velvety smooth transitions.
The newest front, though, replaces the traditional torque converter with a set of clutches that hand off gearchanges from one to the next in a fraction of a second. While these new dual-clutch gearboxes are a performance home run, they are still more costly and complex than their more traditional automatic brethren, so it's not surprising to hear that the famous Bavarian automaker is sticking with the tried-and-true autobox in its volume sellers, for now at least.
[Source: Automotive News - Sub. Req.]