A trademark name for a form of semi-automatic transmission. It combines an automatic transmission with the gear-shifting feature of a manual transmission without the use of a foot-operated clutch . In the normal automatic transmission drive mode, the transmission behaves like any other automatic. The manual-shifting feature allows more control over the full range of rpms an engine offers. Porsche and Audi offer a related transmission technology called Tiptronic. The Lexus GS400 also has a similar transmission but instead of using a stick to change gears it employs buttons on the steering wheel. Several other automakers offer similar technologies.