One of the most effective fuel saving functions on the latest Scania models, due in Australia in a couple of years, is free rolling when power is not required. If the truck is travelling at cruise speed and has enough momentum to maintain speed, the transmission neutralises and the rpm levels drop to 500.
This is further enhanced by another feature, the truck can have topographical information about the roads, on which it is travelling, already preloaded into the system. When the rolling feature is active, the truck knows the road will slope for some time, so keeps the transmission neutralised for longer, knowing speed will be maintained by the grade around the corner.
Conversely, when the truck knows an upgrade is approaching, it will hold onto a gear and ensure the right rpm level and gear are engaged at the foot of the climb to maintain momentum and get up the grade as efficiently as possible.
On the down grade the engine brake and retarder blending Scania have been using for some time, continues to be effective and easy to use. Also when approaching a road junction, the driver simply pulls on the retarder control to get the truck to slow right down to the right speed to make the manoeuvre. If the truck needs to stop, then the driver can go for the brake pedal.
Retardation is also an important part of the active cruise control. If a vehicle in front slows, so does the truck. If it hauls the anchors on, the truck will blend in engine braking and service brakes down to 15 km/h, but not to a halt. Getting a complete stop is on its way, but not available in the first wave of New Generation Scanias to be released.
Out on the road with these trucks, it gives a driver a clear idea just how many small improvements have been made to get the whole truck into the next generation. The most obvious example from the driver’s seat is the way the Opticruise AMT changes gear. We are used to AMTs which make split second changes, well, Scania’s just got quicker again.
The new Opticruise now includes a layshaft, a second shaft running parallel to the main shaft, to and from which drive can be transferred, this improves up shifting. The new system can synchronise the speed of the main shaft and the gear, almost instantaneously, making for very swift changes. On a slight up grade with 60 tonnes on board the power is hardly interrupted on an up shift.
Power and, especially, torque are the two factors which make the driver’s life more comfortable out on undulating country roads. The countryside on the Diesel News test drive is well forested and dotted with lakes and the route is constantly climbing out of one catchment into the next. The power available kept cruising speed high, when needed, and the torque kicked in to pull the load over the hill.