ZF 8HP transmission

8HP is ZF Friedrichshafen AG's trademark name for its 8-speed automatic transmission models with hydraulic converter and planetary gearsets for longitudinal engine applications.

Designed and first built by ZF's subsidiary in Saarbrücken, Germany, it debuted in 2008 on the BMW 7 Series (F01) 760Li sedan fitted with the V12 engine.

Another major customer is Stellantis, who both received a license to produce the transmission and set up a joint-venture plant with ZF.

Efficiency improvements over the pilot design and the first generation include a wider ratio span of 7.81, reduced drag torque from the shift elements, reduction in required oil pump pressure, and broadened use of the coasting and start-stop systems.

[9] Major improvement is the transition to a versatile modular system that allows vehicle manufacturers to comprehensively and flexibly electrify their models as required.

Plug-in Hybrid options with up to 160 kW (215 hp) and 280 N⋅m (207 lb⋅ft) are capable of saving up to 70 % of carbon emissions compared with a purely conventional variant of the 8HP according to the Worldwide Harmonised Light Vehicles Test Procedure (WLTP).

On the other hand the selected gearset concept offers 2 to 3 gears more than conventional transmissions of comparable manufacturing costs, which more than compensates for the weaknesses.