Land Rover trots out the world's first 9-speed transmission
Known as the ZF 9HP, the transmission is designed for transverse use as the most efficient and advanced transmission ever in a production vehicle. Land Rover has teamed directly with ZF on the transmission project.
The brand’s current line of vehicles all use a six-speed tranny, and boosting the number of gear ratios to nine will not only produce fewer emissions, but will also improve efficiency.
The smaller increment between ratio steps also enhances response during acceleration with quicker and highly refined shifting. The higher ratio of the top gear saves fuel by lowering engine speed and also reduces noise, thus adding to occupant comfort when cruising at freeway speeds.
The robust nature of the 9HP transmission expands upon the all-terrain prowess expected of a Land Rover while still delivering high levels of refinement and efficiency. The bottom ratio level in the 9HP is far lower than the current six-speed, optimizing the brand’s vehicles for their established forté – off-road use, towing and especially the steep grades found on some highways
The previous incarnation of the Land Rover six-speed would downshift in sequence, but the new 9HP can skip gears to accommodate more rapid deceleration. Should the driver try to downshift when moving too fast for a gear, the transmission will make the shift as soon as engine speed drops to the proper level.
A Fast-Off mode, by measuring the rate of throttle release, learns to anticipate the driver’s automotive performance style, i.e. the demand for additional power, holding a gear as needed to provide the desired torque.