Having introduced an 8-speed transmission on the new Range Rover and Discovery, Land Rover is upgrading its technology again in its pursuit of extracting higher fuel economy, lowering emissions and providing a better driving experience on future launches.
Land Rover will announce the world’s first 9-speed automatic transmission on a passenger car at the Geneva Motor Show next week. The ZF '9HP' transmission, designed for transverse applications, is claimed to be the most technically advanced gearbox used on a production car.
Land Rover worked with one of the world's leading transmission technology firms ZF to increase gear ratios from six to nine. Beside the aforementioned benefits of a bigger gearbox, smaller gear ratios lead to improved acceleration, improved shift quality and refinement. The high top gear, besides reducing fuel consumption, lowers noise while cruising at high speed.
The '9HP' is designed to complement Land Rover's off-roading applications. The lowest ratio on the 9HP is far lower than the current six-speeder and is designed to handle off-road, towing, high altitude and steep gradients.
Whereas the current six-speed transmission shifts sequentially, the 9HP has a skip-shift function for faster downshifting. The torque converter employs a multi-stage damper system for smoother pulling away and better refinement.
The fast adapting shift system sharpens up during brisk driving and slips into an economical regime during sedate driving. Curve Mode, longitudinal acceleration and pedal position are three parameters controlling upshift prevention, the press release notes.
Despite the incorporation of three extra gear ratios, the gearbox unit is only 6mm longer and weighs 7.5kg lighter than the six-speed transmission it replaces. A hydraulic vane-type pump, two dog clutches a newly nested gear set lead to lower weight and tight packaging.
The 9HP is manufactured at ZF’s Gray Court facility in South Carolina. Land Rover has not elucidated on the model lines the new gearbox will find application or on the tentative market launch. The donor model used to premiere this technology to the world next week at the Geneva Motor Show is the Range Rover Evoque. We will find out more about the new gearbox from Geneva, so stay tuned to IndianAutosBlog.com.