Cummins is continuing its dual-track approach to 2010 emissions rules. Medium-duty engines will be fitted with SCR aftertreatment systems to meet the new limits on NOx while heavy-duty engines will rely solely on enhanced EGR technology.
Its heavy-duty lineup for 2010 will include the ISX 15L, as well as 11.9L and 16L models. Medium-duty engines for '10 will include the ISB (6.7L), ISC (8.3L), and the ISL (8.9L).
Cummins has reported that field-testing with customers of both medium- and heavy-duty engines began this spring. At this point, the company expects its EPA 2010 engines “will have comparable fuel economy as today's proven products.”
As to the potential impact of its 2010 engines on other vehicle systems, Cummins says there “may be increased heat rejection on a few, specific ratings due to the increased EGR flow rates. We are confident that the Cummins on-highway EPA ‘10 products will fall within available vehicle cooling limits.”
According to Cummins, its on-highway engines are an evolution that began in 2002 and were further refined in 2007. Cummins has consistently delivered equal or improved intervals, performance/driveability, reliability and durability, and will continue with the EPA '10 product.
“From a maintenance perspective, the 2010 ISX for heavy-duty applications is almost identical to the 2007 ISX,” said Cummins. “Customers can expect continued ease of maintenance, same maintenance intervals, and minimal incremental technician training to support the EPA '10 on-highway engines.”
The engine maker notes that the addition of SCR to its medium-duty engines for 2010 will meet the near-zero 2010 emissions standards. This will require the use of urea, but “maintenance intervals, performance, durability and driveability features remain unchanged.” Diesel exhaust fluid (DEF), or urea, is expected to be broadly available throughout the U.S and Canada.
The company also told Fleet Owner that it is “making modest investments in our heavy-duty engine business capacity in response to expected increases in NAFTA heavy-duty truck production and higher market share vs. the last [emissions] cycle. Cummins will continue to work closely with our customers to define volume requirements and to right-size our capacity going forward.”
Detroit Diesel Corp.
Roughly 40 trucks powered by 2010-compliant Detroit Diesel Corp. (DDC) are accumulating miles as part of an internal reliability test fleet operated by DDC and its parent company, Daimler Trucks North America (DTNA). According to David Siler, director of marketing for DDC, they'll be operated through the summer and into the fall before select DTNA and DDC customers begin receiving demonstration trucks in the fourth quarter this year.
Siler notes that DDC's SCR-equipped engines performed as expected in winter tests. Also as expected, the urea solution used to reduce oxides of nitrogen (NOx) emissions down to the required levels — called ‘diesel exhaust fluid’ or DEF — froze when temperatures dropped to 12 deg. F and below; however, DDC's test found that the solution would thaw rapidly during engine warm-up and lost none of its effectiveness.
“Letting it freeze did no harm to the solution or the SCR system,” Siler explains. “We found letting it freeze and then thaw on warm-up works better than providing tank heaters to keep the DEF in a liquid state. There's no need to waste energy to keep it a liquid, and the EPA agreed with our approach.”
DDC's road testing so far is finding that SCR can help fleets gain back fuel economy on the order of 3-5% in some cases. “That's due in part because, since we can eliminate NOx downstream, we can allow the engine to produce more of it,” says Siler. “And producing more NOx allows us to reduce the formation of particulate matter [PM], meaning less active regeneration is needed for cleaning the diesel particulate filter [DPF].”
For example, Siler says a typical 15L DD15 engine uses roughly 2 gal. of fuel per active regeneration, which occurs every 325 mi. or so. With SCR, however, that active regeneration interval is now approaching 2,000 mi. — saving fuel and helping the DPF stay in service much longer.
The key right now, says Siler, is putting together a gauge “package” for the SCR system that will be easy to view and understand by drivers and fleet managers alike across the market — from large truckload carriers down to smaller local fleets, for example — to make the “customer interface” as smooth as possible.
“We want drivers, technicians and fleet managers to be completely comfortable with the SCR system. That's our main goal in testing now,” says Siler. “For if we make the transition to SCR easy and comfortable, we hope that by the middle of next year we'll be taking orders for these engines.”
Beginning this summer, Hino Trucks, a Group Toyota company, will be expanding its testing of SCR vehicles in the U.S., according to Nick Vermet, sr. vp sales and customer support for Hino. “We began U.S. testing with two SCR vehicles back in October of 2007,” he says. “This late summer, we will be running another six SCR durability test units.
“These will be in customer hands for real-world, day-to-day, revenue-producing service,” Vermet adds. “One Class 7 unit with a sleeper will be in an expeditor operation; one truck will be based in Texas for warm-weather testing; one will be in Canada for cold-weather testing; one will be near Denver for high-altitude and mountainous terrain testing; one will be in southern California; and one will be near Philadelphia in a regular, lease fleet operation.”
This second round of SCR testing should last six to nine months, according to Vermet, but it does not necessarily mean that SCR is definitely Hino's solution of choice for 2010 compliance. “The final decision about 2010 will be made the end of this year; our engineers are still evaluating other possible avenues for compliance, including EGR,” he notes. “Hino truck engines already use EGR now to help meet existing emission requirements. Although EGR-only 2010 solutions are not being tested here in the U.S. right now, evaluation of EGR is continuing globally.”
It is premature to talk about 2010 pricing, Vermet adds, but nonetheless points out it is always a consideration. “We are keenly aware of the fact that pricing is very competitive in the medium-duty market,” he says.
Both SCR and EGR solutions for 2010 compliance are still on the table at Isuzu Commercial Truck of America, according to Todd Bloom, vp-fleet operations and marketing for the company. “The question is what will be the most cost-effective,” Bloom says. “There was a significant cost increase for everyone in 2007/08 and we expect it will be comparable in 2010. For the medium-duty market, it was in the range of $2,500; that is what we are anticipating this time, as well.
“Several possible 2010 solutions are being tested now, both here in the U.S. and in Japan,” he adds. Japan has a new emissions standard very much like the U.S. 2010 standard that will go into effect in 2009 and a truck fuel economy standard that will be fully implemented by 2015.
A number of next-generation diesel engines are under development at Isuzu, but the basic configurations will not change dramatically from the current lineup, Bloom notes. “SCR may simply emerge as the solution for smaller engines because of the greater cooling requirements for EGR,” he says.
While Isuzu is not yet ready to make its 2010 plans public, the company has no doubts about its ability to meet the 2010 deadline, according to Bloom. “Are we in line for 2010? Are we there? Absolutely,” he says.
According to David McKenna, powertrain sales and marketing manager for Mack Trucks, the company's 2010 field-testing program is going remarkably well at this point. More than 12 demonstration trucks equipped with Mack engines using selective catalytic reduction (SCR) systems to comply with 2010 emission standards are already in the field being used by customers, with roughly two to three per month being added to that number.
Those trucks, he stresses, are with customers spanning all the markets Mack serves: on-highway tractors, vocational tractors, dump trucks, refuse trucks, you name it. “That makes our testing a lot more challenging in many ways,” says McKenna. “For example, the steady state of the over-the-road driving environment of highway tractors is something that's almost never experienced by urban refuse collection vehicles. That's why it's important for us to have all the various customer duty cycles covered by our testing program.”
Still, Mack plans to have all testing complete in time so it can build and deliver 2010-compliant trucks by 2009. One reason for that confidence is that McKenna reports upwards of 3% fuel economy savings gathered from these test trucks from Mack's SCR-equipped engines.
Part of the fuel savings comes from a nearly six-fold extension of the active regeneration cycle necessary to remove soot collected by the diesel particulate filter. With Mack's active regeneration process consuming about a half gallon of fuel, extending the regeneration cycle saves a lot of money over time, McKenna notes.
Another interesting piece of data is that, generally, Mack is finding its SCR system uses 30% less urea — the ammonia-based fluid that reduces oxides of nitrogen (NOx) emissions to the mandated levels when injected into the exhaust — than expected. That means trucks should be able to travel farther on a single tank of urea than previously thought.
To McKenna's way of thinking, longer DEF and DPF intervals combined with the fuel savings being reported now should help make 2010-compliant trucks using SCR an easier sell than many believe.
“Look, there's a price to be paid whichever 2010 solution you pick, in terms of outright technology costs and component packaging needs,” he says. “But right now, based on 100,000 miles of operation, we're looking at returning to an over-the-road user a net fuel savings of $3,500 per year when compared to 2007 emissions-compliant trucks, which includes the cost of urea.”
Helmut Endres, vp-engine engineering for MaxxForce Engines, a division of truckmaker Navistar International Corp., reports that initial field tests of trucks equipped with 2010-compliant engines are not turning up anything unexpected.
While statistical validation testing of 2010 engine models in the laboratory remains on schedule to start by late summer, Navistar is already conducting “captive truck tests” using Navistar-owned equipment and drivers to expose MaxxForce's 2010 grade engines to high altitude conditions, extreme heat, heavy stop-and-go environments, and eventually cold-weather testing by winter.
Laboratory validation is a series of highly aggressive tests that puts the engines under full loads 24/7 for weeks on end, to gain lifetime durability and reliability data under extreme conditions.
Endres says Navistar's evolution of its EGR technology package to meet the 2010 emissions standards generates higher levels of engine heat, requiring more cooling. But overall, Endres notes that few major changes are foreseen for either Navistar's trucks or engines at this point to comply with the 2010 regulations. “For most of our mainstream truck products, this extra cooling capacity fits within the existing engine compartment space on our trucks, so no design changes are needed,” he says. “Only for some extreme models, such as severe service, are any changes needed to handle the extra cooling.”
A big focus of the field test going forward is to find ways to lengthen the replacement interval for the DPF, which captures particulate matter generated by engine combustion. To meet the 2010 rules, MaxxForce is lowering the amount of oxides of nitrogen (NOx) produced by the engine, which means subsequently that more particulate matter is produced. “Our testing is looking for ways to boost DPF capacity so it can handle more soot; that is the main focus of our field work now,” Endres says.
Summer testing so far in high heat conditions — conducted in Las Vegas, NV, and other desert areas of the U.S. — revealed no major concerns or surprises, he adds, noting that such high-heat operation posed the biggest challenge for Navistar's 2010 solution. “It's much more difficult for us in the heat as opposed to cold-weather operation,” Endres says. “We're preparing for winter testing now, and I think that will be much easier for our package to handle.”
He notes that Navistar customers should start receiving demonstration trucks equipped with 2010-compliant engines beginning in the spring of 2009 after planned winter testing wraps up.
“We're going to wait a little longer to give customers trucks so we'll have more mature engine calibrations,” Endres says. “We're striving to maintain the same fuel economy customers get from their current engines. Our biggest hope is that when they start using 2010 demonstration trucks, customers will see no difference compared to their current units.”
Testing of SCR technology in Nissan Diesel/UD Trucks on U.S. highways is still slated to begin in early 2009, though Dave Trussell, the company's director of marketing for its U.S. division, notes that SCR has been in use on UD trucks in its home country of Japan since 2005.“SCR is really a boring story for us at this point,” he says. “In Japan, we've had SCR and AdBlue, the brand name of the urea solution we're using, in place for some time now, so we're not experiencing any teeth-gnashing and hair pulling when it comes to engine or truck engineering issues.”
Trussell says the company still plans to put two to three test trucks equipped with SCR into service in Los Angeles and New York City with moderate highway operation early next year to “fine-tune” its engine/truck package to meet the 2010 emissions regulations.
“The goal, of course, is to get a lot of miles in stop-and-go operation, acceleration and deceleration on highway on/off ramps, plus exposure to cold and hot operating environments,” he notes. “High-cycle metropolitan use is where we'll focus most of our testing, and our feeling is if we can make SCR work smoothly in places like New York City and Los Angeles, we can make it work anywhere.”New York City, Trussell explains, provides more of the classic slow-speed, stop-and-go working environment, whereas Los Angeles takes that environment and adds freeway operations to the mix. “That's a really wild combination, where you have high-cycle stopping and starting along with highway speeds, all in one working area,” he says.
The test trucks will spend time in Phoenix, AZ, for hot-weather tests, as well as Colorado for mountain operations and Minnesota for cold-weather testing. “We'll be giving our SCR-equipped trucks a full battery of tests across all operating environments,” Trussell says.
The lack of infrastructure to supply urea throughout the U.S. for commercial trucks using SCR remains a concern, he says. In Japan, urea is sold in pump dispensers right alongside diesel at the fueling island at about 800 truck stops. “The ability to pull up to a fueling station anywhere in the U.S. and have urea available is the big concern still.”
Trussell reiterated that Nissan Diesel/UD still plans to use the 2010 emissions reduction mandate as an opportunity to redesign its entire line of trucks, especially the cabs, for what will be its 2011 model year lineup.
“It's going to be a sweeping change, resulting in a brand new product,” says Trussell. “The cabs we're operating with now have been out since 1994 so it's about time for a facelift. And with aerodynamics for fuel economy and creature comforts for driver retention more critical than ever, the 2010 emissions mandates presented us with a great opportunity.”
Paccar is continuing apace with development of its proprietary Paccar MX engine line that will allow it to supply EPA 2010-compliant engines to its OEM subsidiaries Kenworth and Peterbilt. The Paccar MX engines will be built at an engine plant under construction in Columbus, MI, that, according to Paccar, will complement the DAF engine factory Paccar operates in the Netherlands.
“Our testing program is extensive and includes engine lab tests, durability track testing, millions of miles of controlled field testing in a variety of applications and environments, and customer evaluations,” a company spokesperson told Fleet Owner. “Our development is focused on producing engines with industry-leading fuel economy. The stricter emissions standards will influence the cooling, chassis and exhaust systems, and we expect to be able to offer a full range of horsepower ratings. Additionally, the onboard-diagnostic (OBD) requirements will drive changes in the electrical systems.”
Paccar said it is “evaluating the maintenance requirements for the 2010 engines” and will test and evaluate lubricity requirements and options for 2010 engines and aftertreatment systems as well. According to the Paccar spokesperson, the company is “working with urea distributors to ensure a nationwide infrastructure is in place to serve our customers [with engines equipped with SCR]. Europe has installed the infrastructure, and it is expected that North America will design a similar framework.”
As to when the first Paccar MX engine will be released to the market, the spokesperson said “we are evaluating the optimum time schedule.”
Bob Christensen, Kenworth gm, has previously stated the OEM is testing pre-production models of the Paccar MX 12.9L engine in T800 tractors in its own rapid evaluation fleet as well as in customer fleets, and expects to accumulate 20-million test miles. “We're testing the heavy-duty engine in a wide variety of applications, terrains and climate conditions,” Christensen said.
“Proprietary engines play a significant role in the sale of new trucks and in the aftermarket,” Peterbilt's Bill Jackson previously stated. He noted that Peterbilt is testing the 12.9L MX in its Model 388 tractors.
According to Ed Saxman, product manager-drivetrain for Volvo Trucks North America (VTNA), the roughly 13 to 15 demonstration trucks equipped with 2010-compliant 13L Volvo D13 engines using SCR systems to control emissions levels are performing as expected so far. “We're meeting our targets in terms of horsepower and fuel economy, while complying with the near-zero 2010 emissions standards,” he says. “These are trucks that are fairly close to production-level vehicles and are performing to expectations.
One difference between Volvo's SCR solution and that of other OEMs is that the company decided to install a heating system for the tank containing diesel exhaust fluid (DEF) — a colorless, odorless liquid containing 32.5% urea (and ammonia compound) — to keep it from freezing when the outside temperature reaches 12 deg. F or below.
Saxman says Volvo is drawing on its long experience with SCR in Europe; all told, roughly 150,000 trucks are on the road in Europe today using SCR to reduced oxides of nitrogen (NOx) emissions — and applying that knowledge to the engines being readied for North America. Yet, minor differences between the base engine in Europe versus what's in place in North America is requiring a lot of “tweaking” ahead of 2010.
“For example, we use DEF tank heaters in Europe, but over there they use a 24-volt system. Here in North America we use 12 volts,” Saxman explains. “As minor as that sounds, it's still a difference we need to account for in our engineering.”
Another challenge yet to be worked out is posed by onboard diagnostics rules currently being debated by the EPA and the California Air Resources Board (CARB). What's being required is the development of extremely sensitive sensors that can detect excessive NOx and PM at very low levels — sensors that are very complex and thus have a higher risk of faults.
In 2010, the federal government wants these “detection sensors” to indicate when those emissions reach five times the acceptable level. In 2013, that threshold gets ratcheted down to three times the acceptable level — with the thresholds continuing to drop through 2019. CARB wants to speed up that timetable, hence the debate between the federal and state government entities.
“That's a pretty big deal in terms of the eventual electronic architecture of the engine and vehicle,” says Saxman. “It's detailed technology.”
Aside from that issue, everything else is going pretty much as planned, he says. For starters, finding available “real estate” on Volvo's highway tractors for the SCR components, especially the DEF tank, hasn't proved to be a problem at all. And by using SCR to reduce NOx emissions in the exhaust system rather than during the combustion process itself has allowed Volvo to recapture a lot of engine power.
“The more EGR you use to control emissions, the lower the power density of the engine gets,” Saxman explains. “By using SCR, we've been able to reduce the amount of EGR and get back a lot of power we lost. The goal now is to really communicate these successes — near-zero emissions with more power and improved fuel economy. We need to start telling that story.”