According to a recent Ward’s Auto article, German manufacturer ZF Friedrichshafen AG introduced a rear-wheel drive eight-speed automatic transmission at the International Vienna Motor Symposium.
The gearbox is “designed to improve fuel economy without sacrificing performance,” according to the article. It marks the industry’s second transmission to feature eight forward gears. The first was developed by Japan’s Aisin Group and is found in Toyota’s Lexus LS 460. The ZF transmission weighs the same and will fit in a similar space as a six-speed transmission.
The gearbox will feature what ZF calls an entirely new shifting concept of four planetary gear sets and five shift elements. It is expected to improve fuel economy by 6% compared to the company’s six-speed unit, and fuel consumption is expected to be reduced by 14% over most five-speed units.
ZF says that the new transmission will be able to handle more torque than its six-speed model. The modular construction allows for an advanced automated clutch system to replace the torque converter. Although ZF refused to name any potential customers, the company did say that the eight-speed unit is compatible with most all-wheel-drive systems and supports the integration of partial (started/generator components) as well as full hybrid-electric powertrains.
Source: Sutton, Mike. (May 7, 2007). “ZF Unwraps 8-Speed Automatic Transmission.” WardsAuto.com. Retreived May 11, 2007 from www.wardsauto.com.