DAF, Mercedes, Scania, Volvo
Comparison: Four 500 HP Trucks
With around 500 HP and the largest driver’s cabs, the DAF XF510, Mercedes Actros 1848, Scania S 500 and Volvo FH500 offer a lot more of everything.
The truck segment can welcome its own S Class. From summer 2016, the Scania flagship will also adopt the moniker normally reserved for Mercedes’ most luxury car model. After the P, G and R, Scania has now released the S Class. This may not be entirely down to coincidence, either. It could have been called the Scania L (for long distance) or the Scania E (for extra). But it wouldn’t be too out-there to suggest that former Daimler Trucks boss and current head of VW’s commercial vehicle division (to which Scania belongs), Andreas Renschler may have had a say in the naming process. It seems he is prying the term ‘S-Class’ from the Stuttgarters for Scania.
The implication would be that high-end luxury trucks are the stomping ground of the Swedes, and not the Stuttgarters. It’s certainly feasible that this is the origin of the new Scania model’s name. The name ‘S-Class’ has long been associated with cars with superior engines, world-beating ride comfort and exquisite luxury. The current price of a Mercedes-Benz S 500 is 90,100 euros (plus VAT).
Testing gets underway without Iveco
A few add-ons to the already generous standard equipment will easily tip the 100,000 euro mark, which happens to be around the price of the new Scania S 500. This newcomer must now prove itself against the more established competitors from DAF, Mercedes and Volvo in our 1000 Point Test. Lining up today we have: the DAF XF510FT, Mercedes Actros 1848 LS, Scania S 500 A and Volvo FH500 – all configured with the largest driver cab option. The DAF, Volvo and Mercedes have all been overhauled – in some cases quite considerably – since their initial launch. DAF has improved the transmission, predictive cruise control and performed lots of fine-tuning. Mercedes has focused on optimising its engine, whilst Volvo has replaced the injection system (finally common-rail instead of pump injection) and installed a lightweight chassis. But where are the other three brands? MAN declined to take part long before the test ("no appropriate vehicles available"), whilst Renault claimed scheduling difficulties. Iveco agreed to take part, yet withdrew 36 hours before the test with a somewhat flimsy excuse.
In comparing the old R-Class with the new S-Class, it quickly becomes apparent that a great many improvements – some long overdue – have been made. The side mirrors no longer shake, the bed is larger and more comfortable, and the miserly cool box (a wobbly drawer) has made way for a spacious, well-built 40-litre unit. There are also more colour options, and general material quality has been improved. Furthermore, the S-Class is the first Scania – excluding the old trucks with long hoods – to feature an even floor in the driver’s cab. This is all great news, and brings the Scania up to the level of the competition. But is it enough to leave them in its wake? Both Volvo and Mercedes are just as adept as Scania at building a good driver’s cab, and score points for a well-constructed workstation and good beds (Volvo), and a massive cab with high quality finishing (Mercedes).
Close call, but the Actros driver’s cab wins
Even the DAF – the oldest model of the four – is a worthy contender. The Super Spacecab feels very spacious and convinces us with its practical, no-frills set-up. All four driver’s cabs are of a remarkably high and similar standard. The differences are – aside from storage space – very small, but can nevertheless still be found. In some areas, the DAF impresses with thick curtains and very practical storage solutions, in others – the front step and steering wheel adjustment – it disappoints. The Mercedes ekes out a small lead with the best finish quality and most pleasant materials. But it too has weaknesses, such as the entry into the high driver’s cab or the highly-mounted ‘floating’ external storage compartments. It is a similar situation for the Volvo and Scania too: minor negatives – such as the small size of the FH driver’s cab – mixed with major positives – such as the enormously adjustable steering wheel of both these Swedes.
Overall, the Actros makes the most convincing case, but the points won here are quickly squandered when it comes to drive quality. Both ride comfort and occasionally the driving dynamics leave something to be desired. Whilst Mercedes was once the benchmark of driveability, both Volvo and Scania now outperform the Stuttgarters’ offering. Two things affect the ride comfort of the Actros. Firstly, the front axle (although probably the front cab suspension), which is unnecessarily hard and restless. This also means that interior noise is far louder than that of the competition. Then, there is the comparatively loud engine. The Scania impresses in this regard, generating only 61 db (A) at 85 km/h (Mercedes 64.5 db (A)).
Scania transmission breaks the mould
Both the DAF and Volvo are also remarkably quiet. Only with the sunroof open does wind noise become an issue after a while. The Scania must once again be commended, this time for its driving dynamics – it runs straight and true, and steering wheel movements are transmitted to the wheels with perfect precision. All in all, the Scania provides a very reassuring driving experience. The Volvo and DAF make similarly positive impressions. The Actros drives indifferently, due in part to the lateral tilt of the high-mounted Gigaspace cabin. Long a standard in long distance trucks – and therefore also in our quartet – are automatic transmissions and GPS cruise control systems. These features are especially decisive when it comes to ease-of-use, economic cruising revs and good consumption figures.
DAF continues to rely on the AS-Tronic from ZF. Whilst the next generation ‘Traxon’ models are indeed better in some areas, the AS-Tronic continues to perform well in the DAF. It always has the right gear ready, shifts up rapidly yet elegantly, has all the necessary extra functions and is even the lighter option. The Volvo gearbox – the I-Shift – can do everything just a little bit better and is also available with a double clutch. In several areas, the characteristics of the Mercedes automatic transmission – the Powershift 3 – are markedly different from those of the I-Shift. Gear changes are sometimes rather rough, and the electronics react with a pronounced delay to any movement on the gas pedal when pulling away. This can be very irritating in some situations. Otherwise, the Powershift is very in tune with the engine’s capabilities, and allows the 12.8 litre OM471LA to run at very low revs the majority of the time. With a synchronised main transmission (the other transmissions do without synchronisation), the Scania marches to the beat of its own drum. The GRS905 twelve-speed gearbox (with two crawler gears) also employs a gear brake on the countershaft.
DAF delivers a good compromise of speed and consumption
In contrast with the well-known Fuller transmissions – where the gear brake is activated by depressing the last centimetres of the clutch pedal – the Scania’s brake engages automatically and results in rapid upshifting. This allows the Scania to accelerate on gradients with no interruptions to traction. The vigorous acceleration (from 0 to 85 km/h) can also be attributed to the gear brake.
You don’t operate this different, yet functionally very similar gearbox. Rather, you politely observe it as it does its job. The same applies to the predictive cruise control of our four tractors. Once set up, they do exactly what they are designed to – masterfully ‘play’ with the lorry’s kinetic energy. In principle, different and selectable ‘windows’ can be configured (i.e. the plus/minus deviations from the selected cruise control speed). Each of the four manufacturers use this feature in their own, slightly different ways. For example, the Actros has one goal in mind – reducing diesel consumption. The DAF on the other hand strikes a very good balance between speed and consumption, whilst opting against the ‘momentum-build’ favoured by the others before an incline.
With the cruise control set to 85 with an overshoot of 5 km/h, Mercedes, Volvo and Scania allow the truck to accelerate past 90 km/h on a downhill slope for a certain period of time, if another incline is to follow. This time is capped at 45 seconds, falling below the requisite time for an entry onto the driver card. However, this practice is not permitted, which is why DAF eschews this function. By Euro 6 at the very latest, a new engine size with a displacement of almost 13 litres and a wide front had become prevalent.
Transmissions are largely tied when it comes to both the number and spread of gears (the relation between smallest and largest gear). The same can be said of axle ratios, which are unanimously between 2.5 and 2.6 to 1 for 40 tonners. In the truck class on test here, where most competitors have around 500 HP, the 476 HP Actros 1848 LS is somewhat of an anomaly. Yet, thanks to Mercedes’ so-called ‘Top Torque’, it delivers an additional 200 Nm and thereby comparable performance in the low-rev range. This extra torque is available between 825 and 1,500 rpm. At the top end, the engine delivers 2,500 instead of 2,300 Nm, yet this is only available in the biggest gear.
Scania proves itself king of the hill
In many situations, the Actros is able to keep up with the competition, but loses speed as soon as smaller gears are necessary. On long inclines, the Actros lost well over 30 seconds. The titles of both fastest hill-climber and fastest overall go to the new Scania S 500, which has a little more torque than the DAF and Volvo (2,550 instead of 2,500 Nm) and a somewhat shorter axle than the Mercedes and DAF. The result of this is that the Scania delivers the best performance in lower and middle rev ranges. Following closely behind are the Volvo and the DAF, whilst Mercedes tails far behind. The Actros knowingly accepts this loss in speed. On the one side, sometimes it cannot go any quicker thanks to a lack of torque, on the other, it often doesn’t want to go any quicker because of the Predictive Powertrain Control system that works together with Powershift to force low revs. Competitors’ systems operate similarly, however only the Mercedes employs such low revs. And they certainly pay off. The Actros 1848, together with the Scania S 500, consumed the least diesel on our test route and achieved the best maximum fuel consumption too. In this respect, the most recent overhaul of the OM471LA can be deemed a success, even if Adblue consumption is slightly higher (increasing from three to five percent).
Datum20. Dezember 2016