ZF CEO thinks 9 speeds is enough
November 6, 2012
by Douglas A. Bolduc
The nine-speed transmission might be where the race to add gears ends, ZF Friedrichshafen CEO Stefan Sommer said.
He referred to nine speeds as the "natural limit" because going beyond that number adds weight and complexity that cannot be offset by gains in fuel efficiency.
"There is no hard line, but you have to consider the law of diminishing returns. The question is whether adding even more gears makes sense," he told the Automobilwoche Congress here today. Automobilwoche is Automotive News Europe's German sister publication.
Not long after ZF introduced its eight- and nine-speed transmissions, a press report said that Hyundai Motor Group was developing a 10-speed gearbox. Last month, a separate report said that General Motors and Ford are jointly designing nine- and 10-speed automatic transmissions for broad use across their vehicle lineups in a bid to boost fuel economy.
Earlier this year, Julio Caspari, president of ZF's North American operations, hinted that a "Can-you-top-this?" race to add gears may be driven by marketing considerations rather than fuel economy.
That's because there is only an 11 percent gap between the most-efficient transmissions today and a theoretically perfect gearbox, he told Automotive News Europe sister publication Automotive News.
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