LAND ROVER SA SAYS ‘NINE’ TO ITS GERMAN (AND OTHER) SUV RIVALS BY BEING FIRST TO MARKET WITH A 9-SPEED AUTOMATIC
- Developed by transmission experts ZF specifically for front-transverse drivelines
- New 9HP transmission cuts fuel consumption and emissions
- A lower first and a higher top gear…yet closer ratios for better efficiency and smoother shifting
In a South African first, the MY14 Evoque marks the local debut of the ZF 9HP transmission – a ground-breaking design which sets new standards. It is fitting therefore that the Evoque, an innovative and class-leading vehicle that set new standards when introduced late in 2011, should be part of this trend.
Compared to previous 6-speed automatic transmissions for front-transverse installations, ZF’s 9HP cuts fuel consumption and consequently also CO2 emissions. The technical basis for the great efficiency of the 9HP is the very high transmission spread – and yet particularly small gear steps thanks to the nine ratios. This not only enhances ride comfort but also makes sure that the engine always runs in the most efficient speed range.
A revolutionary transmission concept uses four individual gearsets and six shifting elements. This required some very innovative packaging and the gearsets are not stacked one behind the other on a longitudinal axis but are ‘nested in’. This concept was supplemented by using hydraulically-operated constant-mesh elements: They can be integrated without major impact on the transmission length and feature a high level of efficiency.
Remarkably, it is just 6 mm longer but 7.5 kilograms lighter than the six speed transmission it replaces.
A torque converter is used as the standard starting element in the 9HP. A multi-level torsion damping system minimizes hydraulic losses by quickly closing the torque converter. With its direct drive it reduces fuel consumption and enhances comfort as well as driving dynamics. Advanced software and extensive testing has reduced shift and response times below the threshold of human perception.
Direct multiple gearshifts are also possible with the 9HP and give the automatic transmission its sporty character: shift points and shift dynamics can be highly variable depending on conditions and driving style. It has also been designed with an eye on the future; and can cope with torque outputs of up to 480Nm, is start-stop capable and can be hybridized. With the torque converter replaced by an electric motor it easily works as a parallel hybrid.
The ZF 9HP is manufactured at a freshly-built plant in Gray Court, South Carolina, USA, using the very latest manufacturing techniques.
