Automatic eight-speed transmissions for the reduction of fuel consumption

Following the introduction of the automatic six-speed transmission range at ZF in 2001 a technically considerably advanced version of these transmissions was launched on the market in 2006 which improved customer-relevant features, such as power-to-weight ratio, reduced consumption as well as response and shifting speed, significantly. With regard to the consistently increasing requirements, it became obvious that further optimization on the basis of the Lepelletier transmission system would not bring the desired results. Therefore, a nouveau automatic eight-speed transmission was developed, which is suitable for eight forward gears with a transmission spreading of approximately 7 and one reverse gear. Due to the good gear efficiency and the fact that only two shifting elements are open in each gear, the system provides all prerequisites for achieving the targets. © Springer Fachmedien Wiesbaden 2007.