[nonsequitur]

With cooperation from ZF Getriebe N.V. Sint-Truiden (Belgium) we have this very good mechanical description of the Continuously Variable Transmission now available.

Download ZF ecoTronic VT1F Automatic Gearbox Description

This document is 31 pages and 1.4Mb in a .pdf format. It has a lot of information in it to let us carefully understand the functions and capabilities of the gearbox in the One CVT and Cooper CVT.

A few people in some of the clubs and here on MINI2 have previewed the Description so I hope you can wade in now to help us better understand this technically-interesting and very capable "heart" in our cars. Look back into this CVT Forum; there are threads where ZF Group, MINIUSA, and BMW Group have answered some of the questions this document raises. We should be able to pull it all together into a much better understanding.

[Jeffy]

I was glad to learn how this transmission works, it's ingenious. The most important fault is the slow reaction to wide open throttle- this needs to be more instant, and after studying the design of the CVT, it could be rectified easily. It doesn't need new software, just that one change: down shift immediately at wide open throttle. We need that in heavy traffic in the U.S. Automatic is the preference in the U.S., so if that were rectified, more people would buy the car. Some Americans REQUIRE an automatic transmission, so it needs to behave like they need. I hope BMW reads this, because more MINIs sold in the U.S. is a good thing for all of us concerned. -Jeffy.

[nonsequitur]

From the better of the technical discussions, here are graphics that show control functions and how a CVT operates:

Continuously Variable Transmission