Dodge tecnology

ZF 8HP transmission

The ZF 8HP is an eight-speed automatic transmission designed and built by ZF Friedrichshafen AG's subsidiary in Saarbrücken. It had its debut in the new BMW 7 Series 760Li saloon fitted with the V12 engine and since then each new BMW model in all Series down to the 1 Series in rear wheel drive and all-wheel drive version was equipped with it.

One of its main aims is to improve vehicle fuel economy, and it can achieve an 11% saving compared to ZF-6 speed transmission and 14% versus modern 5-speed transmissions. Due to changes in internal design, shift times have reduced to 200 milliseconds, along with the ability to shift in a non-sequential manner - going from 8th to 2nd in extreme situations. In the 8HP70 version, it has a torque handling limit of 700 newton metres (516 lbf·ft), and weighs 90 kilograms (198 lb).

Future development will see two four-wheel drive versions available, with version destined for Volkswagen Group applications, using a Torsen centre differential. It will be able to encompass a torque range from 300 newton metres (221 lbf·ft) to 1,000 newton metres (738 lbf·ft), and will be available for use in middle class cars, through to large luxury sport utility vehicles.                      

Chrysler Group LLC initially received the 8HP 8-speed automatic transmissions from the ZF Getriebe GmbH plant in Saarbrücken, Germany. By 2013, in parallel with Chrysler Group, ZF has set up a new transmission production plant in North America, where the 8-speed transmissions will be produced.  ZF Friedrichshafen and Chrysler Group have reached a supply and license agreement for ZF's 8HP 8-speed automatic transmission. Chrysler Group is licensed to produce the 8HP at the company’s Kokomo Transmission Plant and the Kokomo Casting plant, starting in 2013.

ZF designed the 8HP to replace the 6HP—of which over 5 million have been produced—and, in doing so, made the new transmission identical not only in dimension but also in weight (200 pounds). This is an important consideration, as the six-speed is widely employed in the luxury-sport ranks. The 6HP will be out of production by 2014.

ZF says the 8HP is six percent more ­efficient than the outgoing sixer and nearly as efficient as a dual-clutch automated manual, which ZF also produces. However, the eight-speed is roughly 20 percent cheaper and retains the smooth, torque-converter starts to which U.S. buyers have become accustomed. Furthermore, the 8HP has a system to maintain hydraulic pressure even when the engine isn’t running and is therefore the first automatic that’s compatible with stop-start operation—good for 11 percent better fuel efficiency, says ZF. In the CAFE-conscious U.S. market, every percentage point is going to count.