Yes, I confess frankly, under the contribution of GHP to save energy we could previously imagine anything understandable. Of course, you drive with less fuel consumption, if one knows the area. In the valley one accelerates a little more and then gives slightly less gas in the mountain depending on the length. But how should that be possible for a truck with absolute speed restriction?

Overlooked do we have that a cruise control basically needs a bottom speed respectively hysteresis limit for accelerating and an upper hysteresis limit for decelerating. And the Predictive Powertrain Control is going one better still for 20 seconds one km/h in spite of the limitation to 80 km/h. Moreover, it's only available with automatic, so that it can affect the gearshift.

You would like an example? There is the truck or bus in a mountain from which the PPC controller knows how steep and long the is. Is it worth to change down or manages the vehicle it without? Sure, change down costs fuel. Perhaps the truck even has enough drive to engage already the next higher gear.

Who knows closely spaced gear boxes, for example, with half gears, the is aware of, that it is sometimes at steeper mountains more favourable to change down directly by an entire or two gears. And vehicles with multistep automatic are more used to skip a gear as a vehicle with manual transmission, case of the truck still much more common than for passenger cars.

And then downhill. Some routes, even on the highway, the main purpose of the PPC usage, allows a rolling at constant speed. Should be used the engine brake, the correct gear must be selected. All this are possible tasks for PPC. And so can this system also gain momentum in front of the mountain, but only up to the upper hysteresis limit plus one km/h.

Conversely, before reaching the hilltop the lower hysteresis limit is underrun, which is certainly not necessarily in the sense of the behind it driving truck without PPC. But the system has calculated that the downhill drive following behind it, the vehicle let achieve rolling the speed within the hysteresis limits.

According to a statistic from Daimler, the use of PPC makes sense in 95 percent of all highways and even federal roads in Europe. The hysteresis is also not so closely and within the law, as this makes believe a km/h exceedance for 20 seconds. It is namely adjustable the upper hysteresis limit of +4 km/h to +15 km/h and the lower of 0 to -10 km/h. 11/15