The new gearbox, code-named 9HP, is designed for cars with front-transverse drive. It is available in two model ranges and can handle torque between 280 and 480 Nm. It can be combined with start/stop systems, hybrid setup or all wheel drive application according to manufacturer’s requirements. The 9HP is, by default, compatible with stop-start systems without the need for an additional oil pump. It can also be deployed in parallel hybrid architectures, in which case the torque converter is replaced by an electric motor.
According to ZF, the 9HP offers fuel savings up to 16% compared to today’s 6-speed automatic transmissions in front-wheel drive cars. This is attributed to the extremely high total spread of 9.84, and the high number of gears that allow the engine to run in the most fuel efficient speed range. For example, in the 9th gear, one can travel at 120 km/h with the engine running at just 1,900 rpm, compared to 2,600 rpm in a 6-speed auto. ZF states that it has designed all components for faster response and shift times are actually below the threshold of the driver’s perception, even though it uses a standard torque converters instead of the increasingly popular dual clutch configuration.
On a seperate note, perhaps its high time that the 4 speed or even 5 speed auto transmission make its way to the museum.