Harry Plopper

Interesting fact:

ZF & BMW had a goal to develop an auto gearbox that will offer optimal combination of low fuel consumption & performance & smooth shifting. No fixed total number of gears was chosen in advance.

The engineers tested several solutions: from 6- to 10-speed gearboxes. 6- & 7-spped trannies were not efficient enough (to small improvement over current 6-speed auto), while 9- and 10-speed gearboxes even increased fuel consumption. So the most optimal prototype was an 8-speed gearbox. So, it was a perfect choice for production.

I doubt we will see more than 8-speed auto trannies in the future - since they are more fuel thirsty than this optimal 8-speed auto. And car makers tend to lower fuel consumption as much as possible - and will try to do it even more in the future.

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Bartek Sikorski

IMO it's a great idea to have optimal automatic gearboxes to provide a best gear-ratios for best comfort, fuel consumption and performance.

Mirage77

That's interesting. We shall be waiting to see Mercedes produce a 8-speed box then. BTW, is there a reason why Mercedes chooses to produce its transmissions in-house, rather than letting say ZF do it?

klier

I want to know that too. I think the manual up- and down shifting in the new C class with the 7-speed is quite bad.......Overall it's a good gearbox, but this is something they have to work on!

Mirage77

Yeah, it's not exactly they made a better box themselves either. On top of that they have to pay for all the development costs... I have a feeling that for the 8-speed, Mercedes will switch to ZF.

Mr. Mercedes

I've never heard of any problems with the Mercedes Transmission.

As far as how good these new auto's are, they're probably all pretty much the same.

But don't overlook the fact that MB's autos have long been regarded as one of the industries best.

Mirage77

There is no problem at all Mr. M... It's just that the ZF boxes are just as good, if not better.

MB autos in the past used to surpass most autos in terms of smoothness. I had a chance to sit in my neighbour's W124 and I think his auto is still one of the best I've ever experienced - better than the new ones actually, where the gearbox may sometimes be a little confused about when to change gears.

But today, they are all about neck-in-neck, like you said.

YoUhimhER

so lexus was really thinking ahead, by offering the optimal number of gears with its ls, i wonder where all that "too many gears" comments came from.

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