A continuously variable transmission (CVT) is a transmission which can change steplessly through an infinite number of effective gear ratios between maximum and minimum values. This contrasts with other mechanical transmissions that only allow a few different discrete gear ratios to be selected. The flexibility of a CVT allows the driving shaft to maintain a constant angular velocity over a range of output velocities. This 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.

The stop go traffic condition has become synonymous with driving in our big cities. In such a case will automatics transmission make sense to the Indian customer. Well the Indians haven’t taken to automatics like fish to water. The reason being conventional automatics always consume slightly more fuel than manual transmission and the lack of sophisticated automatics.

With the increase in traffic conjunction in the cities stop go traffic has become a big hassle with constant gear changing. In such a situation CVTs or continuous variable transmission proves it usefulness. It is advantageous to use CVT over manual transmission as the engine will always operate at the optimum regime and throttle position. Thereby it could maximize the power output relative to fuel position.

The continuously variable transmission will be commercialized within the next few years. This trial blazing technology has the potential to revolutionize the automotive industry. The superior performance attained by this technology ahs been hitherto unimaginable. The reduction in exhaust emission and fuel consumption make this technology truly amazing and promising.

Many small tractors for home and garden use have simple hydrostatic or rubber belt CVTs. For example, the John Deere Gator line of small utility vehicles use a belt with a conical pulley system. They can deliver a lot of power and can reach speeds of 10-15 MPH, all without need for a clutch or shift gears. Many new snowmobiles and motorscooters use CVTs. Virtually all snowmobile and motor scooter CVTs are rubber belt/variable pulley CVTs.

Some combine harvesters have CVTs. The CVT allows the forward speed of the combine to be adjusted independently of the engine speed. This allows the operator to slow down and speed up as needed to accommodate variations in thickness of the crop.

CVTs have been used in aircraft electrical power generating systems since the 1950s and in SCCA Formula 500 race cars since the early 1970s. More recently, CVT systems have been developed for go-karts and have proven to increase performance and engine life expectancy. The Tomcar range of off-road vehicles also utilizes the CVT system.

Some older drill presses contain a pulley-based CVT where the output shaft has a pair of manually-adjustable conical pulley halves through which a wide drive belt from the motor loops. The pulley on the motor, however, is usually fixed in diameter, or may have a series of given-diameter steps to allow a selection of speed ranges. A handwheel on the drill press, marked with a scale corresponding to the desired machine speed, is mounted to a reduction gearing system for the operator to precisely control the width of the gap between the pulley halves. This gap width thus adjusts the gearing ratio between the motor's fixed pulley and the output shaft's variable pulley, changing speed of the chuck; a tensioner pulley is implemented in the belt transmission to take up or release the slack in the belt as the speed is altered. In most cases, however, the drill press' speed cannot be changed with the motor running.

Unlike traditional automatic transmissions, continuously variable transmissions don't have a gearbox with a set number of gears, which means they don't have interlocking toothed wheels. The most common type of CVT operates on an ingenious pulley system that allows an infinite variability between highest and lowest gears with no discrete steps or shifts.

If you're wondering why the word "gear" still appears in the explanation of a CVT, remember that, broadly speaking, a gear refers to a ratio of engine shaft speed to driveshaft speed. Although CVTs change this ratio without using a set of planetary gears, they are still described as having low and high "gears" for the sake of convention.