A continuously variable transmission (CVT) is a transmission that can change seamlessly through an infinite number of effective gear ratios between maximum and minimum values. This contrasts with other mechanical transmissions that offer a fixed number of gear ratios. The flexibility of a CVT allows the input shaft to always maintain a constant angular velocity
CVT can provide better fuel economy than other transmissions by enabling the engine to run at its most efficient revolutions per minute (RPM) for a range of vehicle speeds. It can also be used to build a kinetic energy recovery system.
Alternatively it can be used to maximize the performance of a vehicle by allowing the engine to turn at the RPM at which it produces peak power. This is typically higher than the RPM that achieves peak efficiency. Finally, a CVT does not strictly require the presence of a clutch, allowing its dismissal. In some vehicles though (e.g. motorcycles), a centrifugal clutch is nevertheless added, however this is only to provide a "neutral" stance on a motorcycle (useful when idling, or manually reversing into a parking space).