How CVTs Work


Transmission Image Gallery

cvtPhoto courtesy Nissan Global
Nissan HR15DE engine with Xtronic CVT. See more transmission pictures.

Some say you can't teach an old dog new tricks. But the continuously variable transmission (CVT), which Leonardo da Vinci conceptualized more than 500 years ago and is now replacing planetary automatic transmissions in some automobiles, is one old dog that has definitely learned a few new tricks. Indeed, ever since the first toroidal CVT patent was filed in 1886, the technology has been refined and improved. Today, several car manufacturers, including General Motors, Audi, Honda and Nissan, are designing their drivetrains around CVTs.

In this article, we'll explore how a CVT works in a typical rear-wheel driven car, answering several questions on the way:

  • How does a CVT compare to a conventional, planetary automatic transmission?
  • What parts does it have and how do those parts work?
  • What advantages do CVTs offer over conventional automatic transmissions? What about disadvantages?
  • What's the driving experience like in a car with a CVT?
  • What kind of makes and models incorporate CVTs?
  • Are there any other applications for CVTs other than automobiles?

First, we'll look at how a CVT compares to a traditional automatic transmission.