ZF DEVELOPS NINE-SPEED AUTO TRANSMISSION

Written by Mike Ryan, Senior Writer

September 24, 2011 11:00 AM AEST

ZF has developed what it claims is the world's first nine-speed automatic passenger car transmission. Known as the 9HP, the transmission is an all-new design, which comes in two model ranges for front-traverse installations, covering a torque range between 280- and 480-Nm.

Testing has indicated that the 9HP can obtain fuel consumption savings of up to 16 percent over contemporary six-speed transmission. While running at 120-km/h, the 9HP uses only 1900-rpm, while a six speed transmission requires 2600-rpm to operate at a similar speed.

The system can also be specified in an all-wheel drive configuration, with further fuel savings achieved by using ZF's decoupling function, which only engages the rear axle when it is required. The 9HP is equipped as standard with a ZF developed torque converter for smooth take-offs, while the short gap between gear changes lends itself to quicker response and shift times.

For hybrid applications, the torque converter is replaced by an electric motor, resulting in a straight forward installation.