Increase fuel mileage 20% and GM appproved it...so where is it?

Question

A British firm has developed a new form of automatic transmission that it says can cut fuel consumption on SUVs and trucks by 20 percent when compared with a conventional automatic gearbox.

The company, Torotrak, says that the cost of its Infinitely Variable Transmission is comparable to a conventional auto box, and it is looking for an American company interested in building the units for sale to American manufacturers. GM has already tested the Torotrak system and approved it, and although the company is not prepared to build the transmissions itself, it would be prepared to look at proposals from any of its Tier 1 component suppliers who were prepared to undertake manufacture of the gearboxes.

The Torotrak transmission differs from a conventional automatic in that it has no torque converter. The torque converter transfers the drive from the engine to the gearbox by means of a fluid coupling that takes the place of the mechanical clutch used in manual transmissions. The fluid allows the drive from the engine to "slip" while the car is at rest or while shifts are being made, thus making it unnecessary to disengage the drive using the clutch.

Pretty amazing...this revolutionary product has been around since 2002!

More Info: http://www.thecarconnection.com/Auto_News/Daily_Auto_News/Torotrak_The_Next_CVT.S173.A5029.html

Answer 1

There is a new Saturn model with this technology...it basically removes the transmition from the equation when you are stopped/idiling....not all that exciting when you think about it, you can do this yourself if you're paying attention although an automatic system is easier and more convenient.

Answer 2

da vinchi came up with the idea for CVT a long time ago, used in some cars in the 80's. redeveloped in 2002. still not better then what's currently used. often weights more, has a limited life, special lubricant that costs more, extra mantinance required, special mecanics are needed to work on the CVT.

(I've heard that there is a bike called the da vinchi that uses da vinchi's CVT design)

all in all it costs more over the life of the car then the gas savings. (someday that might change...just not yet)

Answer 3

I'd forgotten about this design.  

Offhand, I'd guess that GM is hesitant because those swash-plate 'variators' look like they're no fun at all to lubricate.  The forces between the cam followers and the swash plates would be enormous, which means that there would be durability issues.  

One of the great advantages of the fluid coupling used at present is that it doesn't wear out.  Conversely, one of the problems of continuously-variable transmissions is that they do wear out, despite heroic attempts to develop adequate lubrication.

Answer 4

Seems to me there are several vehicles already in production with CVT's.