For some time now, members of the auto industry have been racing to add gears to automatic transmissions in a quest to develop the theoretically perfect gearbox. But for a senior executive at transmission specialist and automotive engineering giant ZF Friedrichshafen AG, the race could soon reach a cul-de-sac.
As for the reason, Julio Caspari, president of ZF's North American operations, told Automotive News that adding more gears may fail to enhance fuel efficiency enough to justify the cost. Caspari hinted that the "Can you top this?" race to add gears could be accelerated by marketing considerations rather than fuel economy.
Caspari said that there is only an 11 percent gap between the most efficient transmissions today and a theoretically perfect gearbox. The ZF executive said that producing gearboxes that epitomize a perfect transmission would be very expensive. ZF commenced producing eight-speed transmission in 2009, developed for cars and light trucks with longitudinal engines and that provides 11 percent better fuel economy than a standard six-speed automatic.
Chrysler Group made news when it adopted the gearbox for its Chrysler 300 and Dodge Charger vehicles. ZF will begin producing its nine-speed transmissions in 2013, while Chrysler will produce both the eight- and nine-speed gearbox under license at its own factories.
According to ZF, the nine-speed gearbox, developed for transverse-mounted engines, provides 16 percent better fuel economy than a standard six-speed automatic. Chrysler plans to use nine-speed transmissions on all of its front-wheel-drive models. On the other hand, Hyundai Motor Group was reported to be developing a 10-speed gearbox. Caspari, however, seems to not be bothered by the report, as ZF will next focus on upgrading its eight-speed automatic transmission. [source: Autonews]