The climb up Mt Slide on the Melba Highway in Victoria’s Yarra Valley is a stern test of any truck and in this instance the DAF we were piloting was digging deep and powering up the steep climb to the summit at the Healesvill Kinglake Rd.
This was no ordinary DAF, this was the much vaunted and anticipated DAF XG+, powered by an all new engine with a punchy 15 litres sitting under the cab pushing out 660 horse and 3200 Nm of torque.
While some speculated that Paccar via its DAF subsidiary in Holland would potentially develop a 15 litre version of its proprietary MX engines, which come in 11 and 13 litre form, Australia appeared to be the only realm in the Paccar empire that needed and wanted a 15 litre.
It seems that while DAF’s Euro rivals particularly Volvo and Scania have made much fuss about their big banger 700 plus horsepower diesels, the reality, as Paccar execs explained, is that the actual number of high horsepower high capacity diesels sold in Europe is fairly low.
“The Scandanavians have a market in their own countries but the main market in Europe is quite small,” said Paccar Australia chief engineer, Brad May.
“The European market for heavy trucks is about in the 250,000 to 330,000 units per year, and the big engine market, is like 10,500 trucks per year, so it’s not even it’s 3 per cent of the total market, so its quite small,” he explained.
“For whatever reason the Scandinavian region takes good chunk of those big engine trucks so they look after their home market, but apart from that the numbers just don’t add up, “ May continued.
“The DAF guys would say you would only spend the money on that if you want to take on the Scandanavians in their own markets, but if DAF had a 15 littre in the MX range , they believe they would only sell about 1500 each year in Europe.”
“Of course, the truth is, even if you had a very good 15 or 16, litre truck, and you tried to sell it to Scandinavians, they would mostly going stick with their Volvo or Scania for any one of 15 reasons, “ May concluded.
Even the US market, where Paccar is a mighty force with its Kenworth and Peterbilt brands, is mainly a 13 litre market, given the US regs confine most semis to be singles with a max GVM of around 40 tonnes. So developing a 15 litre MX would have been a lot of money for not much gain, particularly given the changes to truck power trains that are hovering over the horizon.
That rationale didn’t help Paccar in Australia where our higher loads, challenging road conditions and multi trailer combinations often demand a 15 litre with 600 plus neddies.
The DAF brand has made some strong gains in the Australian market in recent years with Paccar using the advantages it has built up over the past five decades of making and selling trucks in Australia, including an extremely strong customer base in the heavy duty sector, an even stronger dealer network and an ability to adapt trucks for this country’s peculiar and demanding requirements.
However despite the Dutch brands gains it still doesn’t quite match the success of Scania nor the largest share enjoyed by Volvo, although it does often take the fight up to Daimler’s Mercedes brand.
The reality is that the DAF brand was bumping up against the high horsepower glass ceiling and not being able to match the horsepower and torque numbers of those other Euro brands meant it was always going to struggle to take more sales off those brands.
Having said that, while big engine trucks have a bigger share down under, it are still in the minority when it comes to heavy duty.
“We tend to think in Australia that we’re so efficient, and it makes so much sense, but the reality is, we’re a unique market, and it’s a unique market that doesn’t have enough return on any sort of investment, so there is this notion here of either needing to have the ability to design the truck you need, or inheriting the truck you’ve got, and to be able to get the truck you need takes, takes an investment,” Said Brad May.
“You’ve got to have the capability, which we’ve always been fortunate that we’ve had the engineering capability here at Paccar Australia , and we’ve got some corporate parents, who are fans of what we do, and that’s because we put some money back in the bank at the end of the year, so that’s important,” he added.
“I guess we’ve showed we’ve got the ability to return it through sales, because that product we produce is good, however there’s numerous examples, where those pillars hadn’t been put in place and a product is brought in that’s not been designed for Australia, and the sales results normally don’t show success,” said May.
So how to deliver a high horsepower version of the DAF to potentially take more sales from the likes of Volvo and Scania and to be competitive in the B-Double line haul market without hoping or expecting the Dutch would deliver a 15 litre donk?
Enter Paccar’s long term power train partner, Cummins. The Paccar- Cummins alliance has born enormous amounts of fruit for both brands over the years with the US engine maker now the major supplier to Kenworth in Australia as it is in the USA. The Paccar marriage with Cummins hasn’t always been smooth sailing and a perfect relationship, just mention EGR to any Paccar exec or dealer, or for that matter a Cummins operative to see them break out in a cold sweat and start shaking.
That EGR episode was a long time ago and the alliance is pretty strong now, particularly given Paccar customers no longer have the choice of Caterpillar or Detroit power plants when they order their Kenworths any more.
So Paccar engineers being the pragmatic decision makers they are, turned to Cummins to give the new DAF XG a higher horsepower injection using a very much adapted version of the engine maker’s X15 power plant. To demonstrate the mobility and nimbleness of the Paccar engineering team at Bayswater, the amazing total budget for engineering and adapting the Cummins 15 litre was just $AUD10 million. Now that is still a substantial amount of money for the Australian outpost of the Paccar global empire, but the bean counters in Seattle stumped up the budget and the project was underway.
Just how many DAF XGs with a 15 litre the company will sell is a question that local Paccar execs were reticent to answer, however local product planning director, Ross Cureton said the company went through a lot of analysis and number crunching before deciding on the route it has taken.
“We did a lot of analysis because we wondered is 660 horsepower enough and DAF engineers say, well we’ve got a 540 horsepower, 13 litre, and so we analysed that in some depth, looking at how many of the 700 plus horsepower engines are sold here and that sort of thing, and we completely understand and agree with the notion that high torque would be a good fit and offer good performance. However there is a sweet spot, and, you know, we think you can keep feeding a 13 litre more fuel, maybe it could deliver fractionally better trip times, but that’s not really what gets the work done, said Ross Cureton.
In the extensive test program that Paccar Australia has done in developing the 15 litre DAF, which has seen the test trucks log more than three million kilometres, including a lot of those in actual fleet work, some of the die hard Kenworth drivers behind the wheel of the big engine Dutch truck would say they didn’t think the truck would climb hills as fast as their usual Kenworth mounts. However May and Cureton revealed that with the enormous amount of telematics data the company now has in this country, a lot of the ‘seat of the pants’ judgements drivers have quoted have been disproved with cold hard facts.
“Well, we can go into the telematics data and drag up everything for all our trucks in the last couple of years, and compare runs on that same road, over that same hill, in that range, at that mass, with those speeds, and saw that the DAF XG was at or above average.
“ With respect, the claims are not true, maybe the old truck is quieter and they don’t think it is going as hard , because I think noise is a big factor with that thinking that noise equals power, and I think you’ll find when you drive it, that you you don’t get the same impression of power and torque in this as you might in the same engine in another truck,” May tells us.
Paccar closely looked at all the data , and saw that it the numbers bear it out, because with 1000s of Paccar trucks going over that same hill they were able to build a heat map up and even though the trip times varied, because of different situations, such as headwinds and other variables, the data on the 15 litre DAF showed it was near the top of that cloud every time.
Ross Cureton said the development of the DAF XG and XG+ with the 15 litre was very much data driven with the Paccar Connect system giving the engineering team at Bayswater an enormous amount of information and data relating to truck performance, speeds, weights and fuel burns, to inform their decisions about the specs, and many other aspects of the truck and the environment it will operate in.
Cureton told us the development of the new XGs came as a result of DAF anticipating the regulation changes in Europe, optimising a truck around that regulation change, even though it wasn’t yet in place.
The regulation change allowed the prime movers to be about half a meter deeper from bumper to the back of the truck without an overall length law, with the only proviso being that they had to maintain the turning circle which is what led them to develop this XG cab in particular.
The point of this was to improve aerodynamic performance, and according to Cureton, it had the side effect of offering the potential to have more space. However the other legislation that was swirling around was improvements required for trucks in terms of direct vision and being able to see more out of the truck cabin.
Cureton explained that with those two things, they delivered the opportunity to make the cab deeper and also to deliver better vision, giving DAF the opportunity to completely redesign the truck cab.
“They actually changed the metal structure underneath, and I got my first look at this platform in about 2018, it was still clay models and seating bucks so it was very early stages,” Ross Cureton added.
“I could see it was going to be a great 13 litre and a great 11 litre truck, but also that it could be a really great 15 litre, so that was in our mind from the very beginning,” the Paccar product planning director told us.
Cureton also explained that the EU did this study here, to see just how long does the truck have to be to maximise fuel economy and aerodynamic, and from this they settled on a half a metre extra length to improve aerodynamics.
“Apparently all the OEMS helped the European Union to understand that this increase was probably the right balance between a cab more space inside, as well as better economy and performance, while still making it a functional truck that could get around tight cities like they have in Europe,” Cureton said.
“Thad saw the road to really improving the truck’s aero with this design ike how they were managing the transition to the trailer and the roof design, all that usual stuff that the truck companies obsess about,” he added.
Cureton tells us that the front corner radius is much larger than a European truck normally would be and that the cab actually tapers out to the full width through the door section, which he says is where they get the fuel efficiency.
It actually amounts to a 22 per cent improvement in aerodynamics while the Increase in length also gives you more interior space. DAF actually built a new a completely new cab manufacturing facility to build the new cab, which was a ground up clean sheet of paper design.
“One of their objective was to make this bigger XG cab, no heavier than the XF that it is replacing, they almost pulled it off , getting to within 20 kilos, which is pretty good for something that’s significantly better on fuel,” Cureton said.
Paccar invested about $1 billion Australian in the new cab plant in Holland, which is highly automated and robotised ensuring high levels of build quality overall.
“So we moved to the idea of looking at the XG as an opportunity for an Australian developed 15 litre line haul truck, and we never do this stuff in a bubble on your own, which meant this was going to be a global project,” he said.
Looking at the 15-16 litre market opportunity, Cureton said that Paccar didn’t have a presence there with DAF, but that other Europeans like Volvo, Scania and Benz did, and thart they’ve seen some good numbers in that sector by Australian market volume standards.
“Those numbers aren’t going away and if people are buying a bonneted truck, they’re mostly buying a Kenworth, but if they’re not, they’re buying a European cab-over, and we didn’t have any presence ij the high end of that market,” he said.
“With DAF we felt that was important and this coincided with these trucks emerging, and immediately thought, this looks like a good thing, and initially the X 15 that we’ve used from Cummins for years would be the ideal engine to put in the truck to give it the power and capacity to battle in this market,” he said.
Cureton explains that Cummins was developing a new engine in that capacity range, and it offered more power and more torque, as well as the potential to deliver much better fuel consumption
“This was not just better than an X15, but potentially better than other competitive vehicles in the sector, so these things came together at just the right time,” Cureton added.
“It wasn’t all luck, but there was an element of that, as with anything, the harder you work, the lucky you get, so we thought the stars could align, if you like,” he added.
While Cummins made the metal, the reality was that if you put it in a DAF, it wouldn’t go anywhere, because as Cureton and May explained, there’s a fundamental difference in the way a DAF works to the way a Kenworth works.
“When Paccar puts a Cummins X15 in a Kenworth, the engine decides a bunch of stuff, cruise control, engine, braking, a whole lot of things which it arbitrates, as they call it, however in a DAF, the truck, the vehicle, the cab, if you like, is the boss, and the engine just does as it’s told.
“What we had to do was design that bridge between the engine and the cab, and we had to convince Cummins that they should give up that authority,” said Cureton.
All of the modern systems and technology in a truck today means it is far more complex and its not a matter of just hooking up the throttle to make it go, it’s very integrated.
“This engine is designed for very high peak cylinder pressures, and that gives you the torque, which also gives you better fuel consumption, because you can down speed,” Cureton explained.
He also said that the new engine is also a lot lighter than the X15, in fact, it’s almost the same weight as an MX 13, give or take.
Cureton said that when you put this 15 litre engine in that truck, then in broad terms the physical size and the mass of the engine doesn’t really change things, your front springs, can be the same. it was a neat solution.
“The Cummins has designed the engine block is different to the X15 and is something they’ve been doing in other blocks for a while, such as the X 12, working on the concept, and that is to reduce weight, so instead of all the stiffness coming from the cast block, they. Use a big girdle across the bottom of the engine to hold it stiff and then they manage things like external oil galleries, and so on, which has allowed them to pull quite a bit of weight out of it.
“They ended up with a wider engine, which is some achievement, and a torque curve that looks more like a table, so it gives up peak torque at 900rpm and it’s very flat,” he pointed out.
“It’s really about where they have the torque, and we felt that this engine, having high torque at very low is pretty impressive, but also pairing it with a 16-speed AMT means that many of the European competitors don’t have that many ratios to select from, they have 12 speeds generally,” said Cureton.
“So if you take that high torque at low revs and you pair it with a 16-speed, there’s a pretty good chance you’re going to find yourself in the fat part of the torque curve more often and with this engine even the torque at 600rpm is pretty impressive,” he added.
“It means you can run the engine without over speeding and over revving, and also you can keep the speed down and can get good performance and hill climbing. So even though there are engines with bigger headline numbers from a power point of view in terms of trip time and fuel economy, we feel this is the sweet spot,” Ross added.
Both Ross and Brad conceded that the long delays in Australia finally approving a global 2.55metre cab width regulation cost the project valuable time and money. The project was in a delicate place when a decision had to be made to go with the ten current 2.5 metre rule or work towards the 2.55 metre standard which had been a pending decision for more than a decade.
“Working with DAF HQ in Eindhoven principally with software integration and vehicle validation, and all sorts of things around the vehicle, we had the added uncertainty around the Australian Government’s tardy introduction of 2.55 metre width,” said Brad May.
“There were decision points all the way through, are we going left, are we going right, lots of supplier liaisons as far as the various components that we retain from the truck, be it gear boxes or cooling modules or whatever, but the width rule cost us,” he added.
“It cost us close enough to $AUD 1 million I guess you, because when you run these programs, you have q goal of that’s when we want to launch, and you start working back through milestones, and then you have to work up to decision points that run into milestones, and you get to points where you say, we either delay, which we didn’t want to do, or you make a decision.
“ We got to one of those milestones and Ross and I said, let’s spend the money and we had to develop the whole truck for the 2.5 rule because there was no certainty around 2.55,” he said.
All of the 60 odd DAF XGs that were built and have been out on the road are 2.5 metre trucks, and then he rule change was announced.
“It’s easier for us and less expensive in the long run, and it just works better with taking what is their standard product, so we will revert to 2.55 somewhere in the first quarter of 2025,” said May.
“We had to make that call and commit to the tooling and get all the parts done and go through the selections, that is all a big pain that no one needed to go through andthere’s a big pile of money that effectively goes in the bin, but that’s trucking as they say,” May added with a smile.
May said that Paccar knows from years of doing Kenworths, that trucks optimised for Australia are really “bloody” hard to design because they have to be relatively short by World standards.
“There’s a lot of stuff that you have to find a home for on the chassis, while allowing for trailers to swing, then you have high ambient temperatures and I guess we’ve learned 1001 lessons over over the years,” said May
Pondering some of these things May said that they had to find somewhere to put more AdBlue capacity, because they wanted to make sure operators only had to fill the urea when they were filling fuel.
“That was one of the things, and for instance more capacity is easy to define, but then you’ve got to not only find space on the truck for where the hell it sits, but also then get it designed so you can get a tool, and that’s all crazy stuff, then there is the electrical connectivity, because this is a unique installation,” he said.
“It was a whole new transition as far as technique, supplier bases, all those sorts of things, and I think we’ve been pretty successful in every way.
“When you look at this truck, you don’t see you don’t see some sort of obviously hybridized version European truck. We wanted this to both function and appear in every way, like it’s straight out of Europe, as a fully engineered truck from Europe, “ the engineering boss emphasised.
“We wanted no local footprint, or little fingerprints all over the kind of show us something different to that we kind of all the way through joke. But I guess you summarize that with like, every button on the dashboard has to work, full functionality, no compromises. And when you start to get into things like software, that’s where the real work starts.
And then the last part about the chassis layout, the innocuous stuff that needs a home, so where do you put the batteries, where do you put all the air support, where do you put the numerous valves that need to control everything, and all the other stuff?” May added.
“Everything you see in this new XG, we principally led from our very small design team here in Melbourne,
“A critical part of this is that we wanted to end up with the truck we intended to end up with and so with the engine being considerably lighter, that helps with front axle weight with setback axles, which has always been an enemy of European trucks.
“But the decision to go with Air Glide suspension and Meritor 46,000 pound axles has been also quite critical for a couple of reasons, firstly, we take more weight out of the truck, but probably more critical is the Air Glide suspension, which allows us to have a short rear frame cut off, because we wanted a truck that was not compromised by the types of trailers you could put behind it,” he added.,
This means that things like drop deck trailers, which are traditionally an enemy of long rear frame cut off because they become difficult to manage, but not with the shorter rear frame cut off.
“I think the work that went into putting that frame layout together means that pretty it will slide under any trailer, and do so with a strong 1100 litres of fuel capacity and 130 litres of urea, which leads to good range while allowing it to swing both the rear of the frame to the back of the cabin you have a truck that is well adapted to Australian conditions,” said May
With the Meritor axles , the ZF AMT and disc brakes all around the DAF XG. Is a proven driveline.
ZF engineers have spent a lot of time in Australia calibrating the transmission for the new DAF and it shows in the way it drives, shifts and is so well integrated into the driveline.
With basically a seven year program to bring this truck to fruition from the time Ross Cureton first saw the clay models of it and a relatively meagre but still substantial investment of $10 million to develop the truck here in Australia, the people at Paccar can be very proud of the work they have done and the truck they have made possible.
And one more thing that May emphasised was that the cab over opposite number to this DAF in the Kenworth range, the K220 will continue to have its place and that this new XG is not the replacement in waiting for the popular and much loved Kenny cab over.
“We reckoned it was a good idea to make this a 15 litre DAF, so that it can be a particular product and the K220 can remain a Kenworth,” said May.
Backing him up Cureton said that If you do things like looking to put say a DAF cab on the Kenworth, then there’s a real danger you’ll end up with a camel.
“The other thing is that you don’t have a Kenworth anymore, and you don’t really have a DAF anymore either, you’re trying to make something that does both jobs and it’s that hybridisation again.
“ So during all this, we were also updating the k100 to the 220 so it actually has broadly the same electrical architecture underneath as this DAF does and if you put them side by side then most people didn’t guess that, but we think the K220 has its place. The customer base, and the approach is slightly different between most European truck customers and Kenworth customers, and that can remain in place, so we’ll kind of let the market decide if they ultimately want a DAF or a K2 Kenworth,” Cureton concluded.