If you’ve been paying attention to auto industry trends, you’ve probably noticed transmissions are getting more and more gears in order to improve fuel economy. Now, Land Rover has fired the next volley in the efficiency race, claiming to have the first nine-speed automatic transmission designed for a passenger car. Installed in a Range Rover Evoque development mule, the gearbox will be shown off at next week’s 2013 Geneva Motor Show.
The ZF 9HP nine-speed transmission, which debuted in 2011, was specifically designed for transverse engine layouts. Though many other automakers have courted ZF for its new transmission, Land Rover says it was chosen as the lead partner for the project, and worked with ZF to jointly tune the transmission for the brand’s specific needs. By raising the Evoque’s current gear ratios from six to nine, Land Rover says the vehicle benefits from improved fuel economy and reduced emissions. In addition, smaller gear ratio steps deliver more responsive acceleration and more comfort, with ZF describing shifts as being “below the threshold of perception.”
The transmission also needed to be robust to suit Land Rover’s rugged character and all-terrain driving needs. The 9HP’s lowest gear ratio is lower than that of the current six-speed unit and is specifically designed to be used off-road. The transmission was also built to handle towing, climbing grades, and higher altitudes. Unlike most transmissions, which have to shift sequentially, the 9HP has a skip-shift feature that makes downshifting much faster – allowing for greater response when accelerating. An adaptive shifting system is intended to sense and learn a driver’s style, providing sharper shifts when spirited driving is called for and smoother, more efficient gear changes when the mood is relaxed.
Despite having three extra cogs, the 9HP weighs less and is only slightly longer than the current six-speed transmission. No timetable is given for when the 9HP will make it to production, but the technology will be exhibited next week at the Geneva Motor Show.
Source: Land Rover