Land Rover First to Use 9-Speed Automatic TransmissionWednesday, February 27, 2013 6:30 by Arman Barari
Land Rover announced the world’s first production 9-speed automatic transmission for a passenger car. Developed by ZF, this unit is said to be the most efficient and technically advanced transmission ever used in a production vehicle.
Specifically designed for transverse application, this transmission works especially well for Land Rover cars, because it has lower ratios than say a 6-speed, which further enhances all-terrain and all-weather capability, and also results in significant fuel saving. For instance, in 9th gear and 110 km/h, the engine ticks over at below 2000 RPM.
ZF also promises smooth and fast gear changes ‘below the threshold of perception’. Unlike a conventional 6-speed auto that changes gears sequentially, ZF 9HP features a skip-shift function which works in tandem with a multi-stage damper system in the torque converter. What that means is plain English is exceptional refinement.
Another innovative feature of this transmission is the adaptive shifting system, which senses the driver’s inputs and sharpens up under brisk acceleration, or slips into a smooth and refine mode when he or she is driving normally.
Despite having three extra gears the ZF 9HP is only 6mm longer than the outgoing 6-speed, and surprisingly it is 7.5 kg lighter. The reason for that is an intelligently nested gear set, plus two patented dog clutches that replace the bulkier conventional clutch packs.