How do CVT transmissions work?

Question

just curious how they actually do what they do. do they use fluid? require maintenance? better on gas mileage? and anything else cool! thanks everybody!

Answer 1

We have a CVT on the Ford Freestyle and I Love it. You can be cruising on the hwy and watch the RPMs go way down under light load conditions. My other vehicle runs a constant rpm regardless of load (and burns more fuel) because it is a conventional 4 speed. You can find a lot of great write ups on the web on how CVTs work but generally it involves a set of opposing conical gears and a steel belt. the belt is moved on the gears constantly changing the gear ratio. The belt's position can be controlled by hydraulic pressure or a computer. Unfortunately Ford discontinued the CVT on their new versions of the Freestyle (now called Taurus X). I think they were concerned about keeping cost low, although I've heard the perception that a car with a CVT can feel like it has less power (that is to say less pickup) because instead of rocketing forward in 1st gear it will slowly reduce the gear ratio and smoothly accelerate.

here are some links to lean more about CVTs - i'm sure you can find more just search the web for CVT.

http://auto.howstuffworks.com/cvt.htm

http://www.nissanusa.com/altima/#/key-fe...

http://cars.about.com/od/thingsyouneedto...

-Saturday