ZF CEO: We're not chasing 10-speeds

[Zafiro]

Automakers have been adding gears to their automatic transmissions in a bid to boost fuel economy. Ford and General Motors have unveiled plans to jointly develop 10-speed transmissions for use in cars, crossovers, pickups and SUVs. Volkswagen Group also has confirmed a move to 10 gears.

But Sommer said ZF's offerings will top off at nine speeds. The head of the company, one of the world's leading transmission suppliers, spoke this month at a Japanese racing event here, just north of Tokyo.

Fuel efficiency, he said, is derived from the range of gear ratios covered, not simply by the number of gears. ZF's range is wide enough now that incremental gains are difficult.

"We came to a limit where we couldn't gain any higher ratios. So the increase in fuel efficiency is very limited and almost eaten up by adding some weight and friction and even size of the transmission," Sommer said. "We will not go for 10."

http://europe.autonews.com/article/20141126/COPY/311279999/zf-ceo-were-not-chasing-10-speeds

 

[Rolf]

Just before Mercedes Benz brought out the 9G Tronic gearbox its powertrain development manager said exactly the same thing that they won't go above 9 speeds in the future as the weight increase and also gearchange speed/smoothness gets affected by the increase in number of gears wont bring any real benefit in fuel consumption.

 

[martinbo]

9 gears is already a gear too many in my opinion.

 

[Sunny]

Just before Mercedes Benz brought out the 9G Tronic gearbox its powertrain development manager said exactly the same thing that they won't go above 9 speeds

I explicitly remember Mercedes saying the same about 7 speeds (they also said the same about HUD). In general, people have said the same about 5, 6, 7 speeds too... And yes, for a given level of material and engineering progress there is probably an optimum number of gears beyond which the law of diminishing returns makes it not worth it. And that number could possibly be 9 right now. But I doubt it will stay there. Random imaginative example - say it becomes economically and technologically feasible tomorrow to make gears from CF, I bet you could pack way more gears for the same weight.

But OTOH, there is the other side of the equation, with the advent of cars powered by electrical motors that can operate optimally over a wide range of RPM, so do you even need gears?

 

[klier]

But OTOH, there is the other side of the equation, with the advent of cars powered by electrical motors that can operate optimally over a wide range of RPM, so do you even need gears?

The gearbox as we know it is going the way to the dinosaur this century. They better branch out

 

[Sunny]

Talking about right num of gears, imagine where CVT technology could probably have been if FIA didn't ban it in 93 when Williams was testing it in their FW15C.

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[Wunderkind]

Talking about right num of gears, imagine where CVT technology could probably have been if FIA didn't ban it in 93 when Williams was testing it in their FW15C.

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The FIA banned it because Bernie didn't like the noise of the CVT-equipped car. It just went around the track going Naaaaaaaaaaaaaaaaaaaaaaaaaa.

 

[Rainer271]

Ford gets patent for 11-speed automatic gearbox
Patent filed on October 4, 2013
Ford has been granted with a patent for an 11-speed automatic transmission which could find its way inside a model sooner or later.

Back in November 2012, we heard ZF CEO saying a 9-speed auto 'box represents the "natural limit" judging by the benefits brought by an extra gear in comparison to the added complexity and weight. However, the Blue Oval company has already announced a 10-speed transmission is on its way for the 2017 F-150 Raptor and now we have learned their engineers have researched the prospects of adding an eleventh gear.

Ford filed the patent on October 4, 2013 and the document refers to three different transmission configurations using different combinations of gears, clutches and brakes. According to Ford's powertrain spokesman Paul Seredynski, the patent application represents a method of protecting new ideas, so it doesn't necessarily mean they are actually working on an 11-speed automatic transmission.

Source: autoguide.com

 

[Rolf]

I personally feel that the more gears there are in a gearbox then it will get more difficult for the engineers to be able to get smoother shifts as the gearbox will be constantly shifting up and down so many gears during acceleration and braking. I think 9speed is more than enough. I have a 7speed DSG gearbox in my VW CC and that for me is fine and does the job nicely for up and down shifts and smoothness. Also the more gears added will result in a heavier gearbox.

 

[chonkoa]

More Gears:

• More weight- negate fuel efficiency, increases mechanical traction.
  
• Ratios-reduce engine speed to reduce fuel consumption
  
• Engine bandwidth- this is very important because we are beginning to see flatter and broader torque bandwidths which works for and against the case for more gears. With Turbo engines you can literally eliminate some gears on the high end due to the availability of torque over a broad range.

In essence what I do see manufacturers doing in the future is optimising the ratios whilst holding the gear count steady.