Along with a large number of new and further developments of the ZF powershift transmissions, one innovation must be especially mentioned: an Intelligent Range Shift (IRS) for automated synchronous group shifting.
With the aid of an electro-hydraulic valve block and a specially developed software module it is possible to shift the synchronized group transmission of the T-7000 range and its successor generation TERRAPOWER (TPT) automatically in the most comfortable mode. In addition, a semi-automatic shifting or a manual mode at the press of a button (shift by wire) is available.
The IRS also automatically shifts the optimum powershift stage and with that the ideal transmission ratio in the connected gear during the synchronous gear change in all driving situations using the "Speed Matching" function, which is already available in the current models of the T-7000 range. The IRS can be ordered as an option for the whole TPT transaxle range.
In the small models of the TERRAPOWER range (up to TPT 14) four synchromesh gears are shifted using IRS and on the larger models (starting with TPT 16) five synchromesh gears of the group transmission are shifted. The feature of being able to skip gears proves to be an important advantage compared to sequentially shifted transmissions (e.g. dual-clutch transmissions). Therefore at low load it is possible to shift through to the highest gear stage with less gear changes and all that up to a driving speed of 60 km/h - with reduced engine revs.
At 800 ms, the short shifting duration of the ZF IRS gives the driver the impression of a full powershift. The total shifting process divides in the following two parts: gear shift and engagement. The pure gear shift takes only about half of the total shifting duration. This value will not be reached with a manual shifting operation. The duration of the engagement is varied by the IRS depending on the vehicle load and allows a remarkable increase in driving comfort.
