Marketing over efficiency?
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.
A GM spokesman confirmed that the two companies are talking and have signed a memorandum of understanding "to jointly develop a variety of all-new, fuel-efficient transmissions." He would not discuss details and said the companies "hope to announce a definitive agreement soon."
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.
In 2009, ZF began producing its eight-speed transmission, which is designed for cars and light trucks with longitudinal engines. The eight-speed delivers 11 percent better fuel economy than a standard six-speed automatic, ZF says. Chrysler Group will use the eight-speed transmission in the Chrysler 300 and Dodge Charger.
Next year, ZF will begin assembling its nine-speed gearbox in a U.S. plant near Greenville, South Carolina, while Chrysler will produce both the eight- and nine-speed gearboxs under license at its plant in Kokomo, Indiana.
ZF says the nine-speed transmission, which is designed for transverse-mounted engines, is up to 16 percent more efficient than a six-speed automatic. Chrysler says it will use this transmission on all of its front-wheel-drive models.