ZF utilizes several models of 8 Speed RWD transmissions as well as generation one two and three. Initial designations were 8HP30 to 8HP90. Chrysler also adopted the design and ultimately produced the 845RE. Design and capacity differences exist between models. The transmissions are mainly drive by wire and the gear train assembly is modular. Park can be manually operated and models with start stop utilize H. I. S. (Hydraulic impulse storage) system.