ZF Friedrichshafen’s 9HP nine-speed automatic transmission was designed for passenger cars with front-transverse engine configurations. A construction kit principle design allows transmission customization to accommodate various starting elements and all-wheel-drive applications. The setup also can be implemented in space-restricted installation conditions. Model ranges cover 150 to 355 lb·ft (200 to 480 N·m). Four individual gear sets are nested within the transmission, with six shifting elements and nine gears sets. The 9HP also features interlocking dog clutches for power shifting; hydraulically operated constant-mesh elements reduce overall transmission length and optimize efficiency. With a total gear spread of 9.81, the 9HP improves fuel economy and achieves small gear ratios. RPMs are lowered by approximately 700 at a speed of 75 mph (120 km/h), reducing noise. A torque converter is the 9HP’s standard starting element, and a multilevel torsion damper system minimizes hydraulic losses. More information from ZF is available here.