The 6-speed automatic Transmission for Cars

One of the most recent examples of environmentally sound transmission technology is the ZF 6-speed automatic transmission for cars. The integrated mechatronic software analyses the driver's wishes, driving characteristics, and driving situation and derives the optimal response in each case. Weight reductions and excellently coordinated gearshifts reduce fuel consumption five to seven percent with two to five percent better acceleration compared to a 5-speed automatic transmission.
The 6-speed automatic transmission family for cars is a successful innovative leap ahead for ZF, which is exemplary for its development objectives such as greater functionality and power-to-weight ratio. In spite of the increased input torque, the additional 6th gear and additional functions, ZF was able to reduce the number of components by 30 percent and the weight by 11 percent. The greater transmission spread and the adaptive shifting strategy makes it possible to have even more efficient engine management at an engine speed that is favorable for fuel consumption. Through the "stand-by control" function, when the car is standing still, the driveline is automatically uncoupled and the engine runs with reduced consumption

Sophisticated mechanics managed intelligently

The innovative planetary gear set (based on the system by Lepelletier) is at the very center of the ZF 6-speed automatic transmission: three gear sets and six shifting elements were necessary for the previous 5-speed automatic transmission; however, for six gears it is sufficient to have one simple and one Ravigneaux gear set in combination with five shifting elements. Alternately braking and coupling the ring gear, sun gear, and planet spider, results in different reduction ratios.

Optimized step by step

Numerous individual innovations improve the environmental balance of the 6-speed automatic transmission system by ZF. These include extensive computations and test-stand tests to increase efficiency as well as using components made of weight-optimized, formed sheet metal and plastic compound components. Also, contributions to helping the environment are made by lower internal leakage losses through CE pressure regulators, a lower capacity oil pump, as well as low-viscosity transmission oil that can be used for the entire service life.