ZF Friedrichshafen CEO Stefan Sommer said that the nine-speed transmission is the “natural limit” and would mark the end of the rivalry to add gears. He explained that going over nine makes it weigh too heavy and too complicated since it can’t be compensated by improvements in fuel efficiency.
When interviewed by Automobilwoche Congress in Berlin last Tuesday, Sommer said that while there’s no hard line, the law of diminishing returns has to be taken into account. He said that what needs to be studied is if adding more gears is still sensible. ZF predicts that it will achieve huge sales increases in 2013 since the Chrysler Group is making use of its eight- and nine-speed transmissions for high-volume models like full-sized pickup trucks.
Sommer said that with these gains, the German driveline specialist is likely to get some reprieve from the downturn in the European market that’s expected to be worse in 2013. ZF launched its eight- and nine-speed transmissions shortly after. According to a press report, Hyundai Motor Group was developing a 10-speed gearbox. A report last month stated that General Motors and Ford are co-designing nine- and 10-speed automatic transmissions to be used widely across the lineups in an attempt improve fuel economy.
A GM spokesman confirmed that discussions are ongoing between the two companies and that a memorandum of understanding was signed to jointly develop a wide range of all-new, fuel-efficient transmissions. He declined to reveal details but said that a definitive agreement will be announced soon. Julio Caspari, president of ZF's North American operations, hinted earlier this year that there may be a race to top each other up on the number of gears due to marketing factors instead of the fuel economy.