One of the key trends to have emerged from the North American truck market in recent months is the apparent willingness of a broadening scope of truck buyers to consider down-speccing engine displacements in favour of a 13-litre as opposed to the more common – and traditional – 15-litre driveline.
A number of factors are influencing this shift. On the one hand, the additional weight of the post-EPA 10 SCR systems has necessitated something of a rethink in terms of maintaining payload parity. Additionally, as length of haul has reduced – a trend likely to continue with the combined impact of the driver shortage and the opening of a widened Panama Canal – the days of the long distance journey, and subsequently high horsepower vehicles, have diminished. But ultimately, this shift seems to be driven by one key factor above all else. Fuel efficiency is now the key metric – when bundled with total cost of ownership (TCO) – by which a North American truck is now judged. If a 13-litre option allows for better fuel efficiency than its 15-litre counterpart, its attractiveness grows exponentially.
Topography and gross combination weight (GCW) appear equal as determining factors if we take a read across from Scania’s experience in Europe: “In Sweden and in Norway as well, about half of the Scania trucks sold are fitted with the 16-litre engine. The figure for Italy is even higher, so I would say that topography is as important as high GCW when it comes to the use of large engines,” says Scania’s Hans-Ake Danielsson. Italy, Sweden and Norway allow permissible GCW of 50, 60 and 56 tons respectively (110.2 lbs, 132.2 lbs and 123.5lbs) as compared with the US Interstate weight limit of 80,000 lbs (36.2 tons).
“Historically, US 13-litre engines have had poor durability relative to big bore engines,” says Steve Duley, VP Purchasing at Schneider National. Quite often, their life to overhaul is 30-50% less than a 15-litre. The reason for this, however, is not necessarily due to the cubic dimension of the engine.
“One of the best engines we ever operated was the Detroit Diesel S60 11-litre,” says Duley. “We have used 15-litre DDC for best durability and best MPG, but this is because of how DDC has focused and designed the 15-litre versus the 13-litre. We use the 13-litre when we need to reduce overall vehicle weight. We would use the 13-litre if or when it has the right combination of durability and fuel efficiency.”
“We have made the transition to 100% 13-litre and a lot of fleets are starting to catch on,” says Bill Bliem, SVP Fleet Services at NFI. “The 15-litre is still the predominant engine in most fleets though. We were able to make the switch because of our governed speeds as well as the fact that we don’t run the Rockies much. We have no power problems and did it mainly for weight and fuel economy with our direct drive transmissions.”
“In general, the shift to 13-litre engines basically means a shift towards proprietary engines,” comments Chris Visser, Senior Analyst at ATD / NADA. “At present, the majority of late-model used trucks still feature the ISX, with proprietary engines progressively more common in the newer the trucks.
“In terms of residual values, the 13-litre Paccar MX seems to be doing the best in the used market, with buyers paying slightly higher prices for trucks so-equipped in most cases – the exception being the T660, but only by a slight amount. Volvo’s D13 brings higher pricing when paired with the iShift in most models, but when paired with a manual, it generally trails the ISX. International’s MaxxForce suffered severely in the used market, while there isn’t enough information surrounding the Daimler DD13 to comment fairly.”
“Let’s not forget the secondary market’s historical preference for 15-litre equipment and the discounting of 13-litre equipped trucks,” says ACT Research analyst Kenny Vieth. “With 13-litre sales starting in earnest in the second half of 2010, I think it will be interesting in the next several years to see how used truck buyers value 13-litre versus 15-litre units. Right now, the paucity of late model equipment is probably mooting that argument, but when we look a few years down the road, it would not surprise me to see premium valuations placed on 15-litre equipped units.”
“We see an opportunity to lower weight and hence improve freight efficiency by using smaller engines, and even potential for better fuel economy,” says Mike Roeth, of Trucking Efficiency, a joint collaboration between the North American Council for Freight Efficiency (NACFE) and the Carbon War Room.
“Also, as we see aerodynamic drag, on both tractors and trailers, continue to be reduced as well as lower rolling resistance wheels, it simply takes less power to haul the freight,” Roeth continues. “In the recent past and maybe even currently, the truck and engine builders have focused on improving 15-litre power plants and so these engines have remained very good from a fuel efficiency standpoint. We think, due to the opportunities, that a trend will continue over the next years to lighter displacement engines.”
“Daimler Trucks North America is dedicated to providing customers full vehicle solutions that pace the industry in terms of fuel efficiency and lowest real cost of ownership,” says Rich Shearing, Vice President of National Accounts, Daimler Trucks North America. “Over 40,000 orders, in less than one year, for the Freightliner Cascadia Evolution powered by the Detroit DD15 is tangible evidence of this strategy paying off in the market place.
“Both the Detroit DD15 and Detroit DD13 feature best-in-class fuel economy and low-cost maintenance and service. The DD15 is the industry’s benchmark in overall fuel efficiency and is slightly ahead of the DD13. We do not foresee a market shift towards 13-litre engines. However, we will continue to witness customers seeking the lowest real cost of ownership as exemplified by the success of the Freightliner Cascadia Evolution.”
Navistar’s Jack Allen says the OEM expects the overall market for 13 litres and 15 litres “to normalise at about 50/50. That’s where it’s been and that’s our expectation. Within Navistar right now, it’s a little more weighted toward the ISX – I think closer to 60% – and that’s primarily just based on the reputation of the ISX and its familiarity with the customers in the marketplace today. And, the 13-litre with SCR is a new product. It’s performing exceptionally well for the customers that have it. So over time we do expect that ratio to normalise around 50/50.”
Volvo is 91% captive for Volvo powertrain on all trucks built at present, “so 9 out of 10 of our output is powered by Volvo,” says Goran Nyberg, President of North American Sales & Marketing at Volvo Trucks. “We have both our own D16 and the Cummins ISX as a solution, but the dominant engine that we’re selling is the D13. Everyone now knows that the 13-litre is a million mile engine and it’s more about fuel efficiency, torque reliability and average speed and I think we tick all of these boxes.”
The OEM believes 13-litre engine use will continue to grow as motor carriers place a premium on fuel and weight savings, explains John Moore, Volvo Trucks powertrain product manager. “The average engine rating for an over-the-road truck is 450 horsepower and 1,650 lb.-ft. of torque, regardless of displacement. The Volvo D13 model is our most commonly spec’d engine in North America and is available in ratings to 500 horsepower and 1,850 lb.-ft. of torque. Power density and durability of today’s 13-litre engines rival 15-litre engines of just a decade ago. If you compare our production in recent years, you’ll see that the average horsepower spec’d by 13-litre engine customers exceeds the horsepower of the trucks spec’d by 15-litre engine customers.
“With the growing power density of today’s engines, we see great opportunity for motor carriers to look toward 13-litre or even 11-litre engines. By right-sizing their engines, motor carriers can shed hundreds of excess pounds that can be transferred into additional payload,” continues Moore. “On average, a Volvo 13-litre engine weighs more than 300 lbs (136kg) less than competing big-block engines and a Volvo 11-litre engine is nearly 400 lbs less than our 13-litre engine. It’s important to match engine displacement with the operation. While a 13-litre engine provides sufficient power to pull bigger grades, our 11-litre engine is also a very reliable coast-to-coast engine. We still see a large number of motor carriers carrying around unneeded engine weight because they’re operating under the old belief that lower power density engines are more reliable.
“With the push for increased fuel efficiency and struggles recruiting and retaining good professional drivers, we anticipate automated manual transmissions (AMTs) will also grow in prominence. Our Volvo I-Shift AMT, introduced to North America in 2007, accounted for about 70% of all invoiced units with Volvo engines in 2013.”
Speaking during Paccar’s Q4 earnings call in January, former Chief Executive Mark Pigott endorsed Allen’s comments. The OEM secured a share of the 13-litre segment towards the upper end of 30%, he said: “We did high-30%, 37%, 38% and our goal is to keep growing it. As we look at the entire industry of last year for North America, the 13-litre…is about 50% of the market, and the 15-litre is about 50%. And we think that the 13-litre will continue to grow…we’ve now manufactured over 50,000 engines at our Mississippi factory, and it’s doing well on the launch.”
Mack’s Powertrain Product Marketing Manager, Roy Horton, says several factors are used to decide the best engine for the different applications. “These include GCW and topography which define the power and torque needs; and the customer’s business model which defines the cost per mile or cost per hour requirements.
“Inputs include fuel economy, maintenance costs, weight and uptime. The requirements for transport efficiency (cycle times) can be another factor here, and residual value and the planned second life market also need to be considered.
“With Mack’s 1860 lb.-ft. torque rating, we offer an engine that can easily handle all Class 8 segments,” explains Horton. “The muscle of the Mack MP8 has the brawn necessary to manage the toughest loads, but is trim enough that it minimises weight and maximises fuel efficiency. The Mack MP8’s regen system, which enables a driver to stay on the road while the system regenerates, coupled with high-quality performance standards, increase vehicle uptime.”
While it’s very difficult to argue with Daimler’s position that the DD15 in the Cascadia Evolution is now the benchmark product in North America – a market share in excess of 40% makes a very clear point – the gradual pick up in residual value, as evidenced by the Paccar MX, is noteworthy. While there will remain a proportion of the North American trucking industry that will stay wedded to 15-litre specifications for the medium term, there does now seem to be at least a willingness to experiment with a lower displacement approach.