Climbing up into the truck is a familiar experience, and the first impressions of the new DAF XF flagship remind us that the Europeans seem to match each other in step heights and widths, almost to the millimetre.
The new look of these models is much more modern than we have been used to from DAF. The previous model dated from the noughties and DAF in Australia have skipped straight over the first Euro 6 models up to the new models which won the International Truck of the Year for 2018.
There is no mistaking the smoothness both of the driveline and the ride in these latest models. It’s also very quiet inside the truck. The B-double Diesel News was driving was loaded just over 60 tonnes and seemed relaxed heading out on the highway at Yatala, just South of Brisbane.
It has been quite some time since Diesel News took a top end DAF truck out for a test, but this one does bring the brand into the same ball park as the other high performing Europeans, like Mercedes, Scania and Volvo.
Yes, there is only a 13 litre engine under the cab, but there is no sensation of a driveline being over worked as the truck winds up on the highway. The engine is the Paccar MX-13, 6 cylinder diesel engine with a capacity 12.9 litres. The power output of 530 hp (395kW) at 1,600 rpm is complemented by a maximum torque of 2,600Nm (1918 ft lb) available from 900 to 1,125 rpm. The fuel capacity on the truck is just over 1000 litres, with an AdBlue tank capacity of 85 litres.
On the rolling roads going West from Brisbane, this power and torque are more than capable of keeping up the momentum and making an efficient mile. The driving felt relaxed and by this time all of the various auto settings had been made on some of the many state-of-the-art electronic safety system included.
The features fitted on these new trucks from DAF include Active Cruise Control (ACC), Forward Collision Warning (FCW), Advanced Emergency Braking System (AEBS), Lane Departure Warning System (LDWS), Vehicle Stability Control (VSC). This is the kind of level of sophistication the modern truck buyer is looking for.
The relaxed driving style needed to get the best out of the truck is simply a matter of pointing it in the right direction. This gives the driver the time to contemplate the next challenge, climbing Cunningham’s Gap with a fully loaded B-double.
At the start of the climb I tried pushing the accelerator through the detent to get over the message I am looking for maximum power. As the grade increases, the truck is comfortable at 1500 rpm and holding the gear. The message it is on a grade is coming from my right foot and the reading from the inclinometer in the 16 speed ZF TraXon transmission.
The tachometer runs up to 1700 rpm when the grade eases off and then sits back comfortably at 1600 rpm. The system knows how much load there is on board, decides to keep revs high and changes according to its calculations. It is possible to develop a confidence in the system, which is borne out in practise on the climb.
The communication between the engine, gearbox and all of the other systems on this truck are one sophisticated whole which can be trusted to get the job done without fuss and without revving the guts out of the engine. Weight, incline, temperature and many other parameters are going into the calculation the truck is making many times a second.
Climbing the grade the temperature gauge remained unmoved by the pressure being put on it by the two trailers and 60 tonne load it is pulling. This is achieved despite the fitting of taller rear axle ratios to help with improved fuel consumption.
Still in 10th gear the engines runs from 1300 to 1500 rpm and back again at 40 to 50 km/h and the TraXon seems to be in a comfortable situation pulling the fully loaded B-double up the grade. It feels effortless from the driver’s seat. Even on the steeper part of the climb near the summit the transmission lets the revs drop well below 1100 rpm before making a change.
The way this transmission changes gear means there is minimal loss of momentum. There is no nod from the prime mover as the ratio changes. This TraXon transmission makes the shift so quick and smooth the truck simply powers on through.
As the grade steepens at the top, the transmission reads the situation well and grabs three gears at just the right moment to get the load up and over the top. This can be a tricky situation for some systems, the prime mover is levelling out but the two trailers are hanging down the grade. If the driveline tries to speed up at this point and change up, the truck will stall. The TraXon is way too smart to get caught out like that.
Coming down the grade later, the old rule of going down in the gear you used going up saw us take the conservative decision to descend in ninth gear.
The engine brake is on a steering wheel stalk and has three settings. Setting number one shuts three cylinders down to hold you back, two has three cylinders off plus it makes a downchange to get the revs up. Pulling the lever to the third position sees a shut down of all six cylinders and the TRaXon grabs two gears to maximise retardation.
In fact, the retardation worked out better than expected and because the AMT can handle it, the change was made to 10th gear and the speed modulated using the retardation stalk. In fact, toggling between positions two and three made light work of what can be a tricky descent.
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