How Does a Dual-Clutch Transmission Work?

A dual-clutch transmission, also called an automated manual transmission or semi-manual automatic, is a transmission with internal gears that shift using two electro-hydraulically actuated clutches. The vehicle's computer chooses the ratios automatically, or the driver can choose the ratios using a shift lever or shift paddles on the steering wheel.

Although the idea of a dual-clutch transmission was invented before World War II, it wasn't used until the 1980s when race car makers determined that a dual-clutch transmission can respond more quickly and accurately than a human driver could. This type of transmission is now installed in three configurations, and suppliers such as FEV have developed dual-clutch transmissions with electric motors for hybrids.

Many car makers have made use of the dual-clutch transmission, or DCT, including manufacturers like Chrysler, Ford, Nissan and John Deere. High-end car manufacturers, such as Porsche and BMW, have used dual-clutch transmissions that include single-clutch versions. Manufacturers are choosing to use dual-clutch transmissions because of their efficiency, savings in fuel economy and overall performance. Dual-clutch transmissions polarize two groups of people: those who appreciate the manual transmission's dependence on the driver's inputs and those who enjoy the efficiency of manual vehicles but would like an easier way to use them.