Advertisement
Advertisement
Advertisement

Land Rover claims world’s first nine-speed

Company to demonstrate new ZF nine-speed automatic transmission for transverse applications

Published: March 1, 2013, 9:00 PM

Land Rover will demonstrate what it claims to be the world's first nine-speed automatic transmission for a passenger car at the 2013 Geneva Motor Show. It will become available in the 2014 Range Rover Evoque.

Chrysler is also planning to introduce a nine-speed in the new Jeep Cherokee, and has just committed a substantial investment to build the transmissions in Indiana.

The ZF 9HP transmission to be used in the Evoque is designed for transverse applications, and is said to be one of the most efficient and technically advanced transmissions ever used in a production vehicle. Land Rover is the lead partner with ZF on this project.

Increasing the number of gear ratios from six to nine helps reduce emissions and improve efficiency, the company says. Smaller ratio steps also give improved response during acceleration, with improved shift quality and refinement.

A higher top gear improves efficiency by lowering engine speed, which also improves comfort and reduces noise when cruising at highway speeds.

The robust ZF 9HP, which has a lower first-gear ratio than the existing six-speed transmission. is said to complement the all-terrain capability of the Land Rover. It has been designed for off-road use, towing, and on-road conditions like steep gradients.

Unlike the current six-speed transmission makes sequential downshifts, the nine-speed has a skip-shift function for faster downshifting and rapid deceleration.

If the driver requests a downshift when the vehicle is going too fast for the selected gear, the transmission will hold off and make the shift when the speed drops to an appropriate level.

A "Fast-Off" mode measures the rate of throttle release, anticipates further requests by the driver for more power, then holds the gear if necessary.

The 9HP's torque converter incorporates a multi-stage damper system for smoother driveaway and greater refinement.

An innovative adaptive shifting system matches the driver's driving style, becoming crisper during brisk driving and seamlessly shifting to a more economical program in more relaxed driving.

Tightly packaged and incorporating some innovative features, the 9HP is only 6 mm longer than the six-speed and is 7.5kg lighter.

The new nine-speed transmission will be built at ZF's American factory in South Carolina.