Continuously Variable Transmissions

A manual transmission keeps you tuned in to your car. Learn the basics of a manual transmission and explore transmission parts and the inner workings of transmissions.

A CVT has a nearly infinite range of gear ratios. In the past, CVTs could not compete with four-speed and five-speed transmissions in terms of cost, size and reliability, so you didn't see them in production automobiles. These days, improvements in design have made CVTs more common. The Toyota Prius is a hybrid car that uses a CVT.

The transmission is connected to the engine through the clutch. The input shaft of the transmission therefore turns at the same rpm as the engine.

Mercedes-Benz C-class sport coupe, six-speed manual transmission, graphic illustration
Photo courtesy DaimlerChrysler
Mercedes-Benz C-class sport coupe, six-speed manual transmission, graphic illustration.

Gear
Ratio
RPM at Transmission Output Shaft with Engine at 3,000 rpm
1st2.315:1
1,295
2nd1.568:1
1,913
3rd1.195:1
2,510
4th1.000:1
3,000
5th0.915:1
3,278

A five-speed transmission applies one of five different gear ratios to the input shaft to produce a different rpm value at the output shaft. Here are some typical gear ratios:

You can read How CVTs Work for even more information on how continuously variable transmissions work. Now let's look at a simple transmission.