Land Rover will demonstrate the latest in a long line of technical firsts at the 2013 Geneva Motor Show with the announcement of the world’s first 9-speed automatic transmission for a passenger car. The ZF 9HP transmission is specifically designed for transverse applications, and is one of the most efficient and technically advanced transmissions ever used in a production vehicle.
Increasing the number of gear ratios from six to nine gives significant improvement in fuel economy and a corresponding reduction in CO2 emissions. Smaller ratio steps give improved response during acceleration, improved shift quality, drive and refinement. The higher top gear not only reduces fuel consumption but the lower engine revs improve comfort and reduce noise when cruising at high speed.
The 9HP is extremely robust and perfectly complements Land Rover’s rugged all-terrain ability whilst delivering exceptionally high levels of refinement and efficiency. The lowest ratio in the 9HP is far lower than the existing six-speed transmission and is specifically designed for off-road use, towing and more extreme on-road conditions like gradients and altitude, giving the driver a heightened sense of control.
The 9HP is a masterpiece of packaging and despite the extra three gear ratios is only 6mm longer and weighs 7.5kg less than the outgoing six-speed transmission. The small package space is achieved by a number of innovative design features including a new hydraulic vane-type pump, which also contributes to improved efficiency, two patented dog clutches replacing bulkier conventional clutch packs, and an Intelligently Nested gear set.