External combustion

| April 30, 2009

Proponents of the two 2010-compliant heavy-duty engine technologies battled at press events during the Mid-America Trucking Show in Louisville, Ky., in March.

The alternatives will reduce NOx emissions to meet the 2010 U.S. Environmental Protection Agency regulations.

Navistar, the lone engine maker not using selective catalytic reduction to meet the new regulations, lobbed shots at its competitors during an event where it showcased its new 15-liter MaxxForce engine.

SCR involves complexity, payload, packaging, weight issues and hassles, said Dee Kapur, president of International’s Truck Group. “It means adding five new major emission critical components.”

Navistar’s solution – enhanced exhaust gas recirculation – means no added hardware and no new, complex electrical system, he said. For medium and severe-service, advanced EGR is “a no brainer,” he said. Navistar’s 2010 engines will produce 0.5 grams of NOx and will use EPA credits previously earned by exceeding EPA emissions goals to achieve the required 0.2-gram limit.

“SCR is not a new development,” said Chris Patterson, outgoing president and CEO of Daimler Trucks North America, during a panel discussion, in which SCR proponents sought to dispel what they deemed “misinformation” about SCR. Patterson cited the more than 200,000 SCR-equipped trucks Daimler has operating in Europe. The technology “has already saved our customers nearly half a billion dollars in fuel costs, compared to other technologies,” he said.

All engine makers use EGR today, said Denny Slagle, president and CEO of Mack Trucks. “It generates a lot of heat and puts stress on the engine,” he said. “We manage well today, but we’ve reached the limit of what we can do using EGR.”

Engine makers on the panel – Daimler, Mack, Volvo and Cummins – cited fuel savings of around 5 percent compared to 2007 technology engines. Navistar officials concede that the company’s advanced EGR engines can’t match the fuel economy of the SCR-equipped engines of its competitors, but they argue that buyers must consider the fuel economy of the overall package and the benefits of avoiding SCR.

One of Navistar’s biggest arguments against SCR is that for the first time it makes the owner and driver accountable for emissions, Kapur said, because diesel exhaust fluid must be added periodically to maintain appropriate emissions levels. That initially was a concern for the U.S. Environmental Protection Agency, as well, said Byron Bunker, with EPA’s Office of Transportation and Air Quality, “but the industry has done an absolutely fantastic job of answering that concern.”

Bunker said EPA has not endorsed any technology to meet the 2010 standards.

The DEF itself was a source of debate. Navistar officials said the fluid freezes at 12 degrees Fahrenheit and can become a toxic ammonia gas at 122 degrees. But Barry Lonsdale, president of Terra Environmental Technologies, a supplier of the urea used in DEF, told panel attendees that the fluid is non-hazardous, based on Occupational Safety and Health Administration criteria.

“Let’s remember diesel fuel is a hazardous substance,” Patterson noted. DEF “is relatively benign.” And if the DEF is altered by temperature or other factors, “it won’t affect engine performance or fuel economy and won’t harm the after-treatment or engine,” he said.

Referring to media reports that DEF will be available at 500 U.S. fueling stations, Kapur expressed concern about adequate availability. Representatives from Pilot Travel Centers and TA/Petro who participated in the panel sought to allay any concerns. Both companies said they will begin rollout of DEF this year.

Kapur cited after-treatment options under development that eventually would eliminate the need for DEF. But panelists dismissed such technologies. “We don’t see it [happening] on anything close to a reasonable horizon,” said Jim Kelly, president of Cummins engine business.

Engine makers also held their own press events at the Louisville show:

Navistar unveils 15-liter MaxxForce engine
Navistar presented a new 15-liter version of the MaxxForce engine for its International truck brand.

The company worked with Caterpillar in producing the MaxxForce 15, “leveraging a proven platform,” including the block, crankshaft, head and other components of the Caterpillar C15, said Eric Tech, president of Navistar’s engine division. Navistar will add to that foundation the fuel and air systems it developed for the MaxxForce 11- and 13-liter engines.

Caterpillar announced in June 2008 that it will exit the heavy-duty on-highway engine business effective with the next round of emissions cuts in January 2010.

Tech said maximum ratings will include 500 hp with 1,850 lb. ft. of torque as well as a 550 hp version at the same torque level. Both 1,800 and 2,000 rpm governed speeds will be offered.

Five million miles of testing will be done before the MaxxForce 15 is introduced, according to Tech. As a bridge in early 2010, Navistar will use Cummins ISX engines built in 2009 to the extent allowed by the U.S. Environmental Protection Agency, said Tim Shick, director of business and product strategy for Navistar Engine Group. In addition, the MaxxForce 13 will be used for applications that don’t require 15-liter power. Shick expects the 15-liter engine to be available in early 2011.

Noting that Navistar is the only engine maker not using SCR to meet the new emissions regulations, Jim Hebe, senior vice president of North American sales, said, “The competition says we’re on an island. We think it’s more like an oasis.”

Navistar will meet the 2010 regulations using enhanced exhaust gas recirculation and EPA emissions credits.

Cummins adds model to its 2010 on-highway lineup
Cummins Inc. introduced its on-highway engine product line, including the new ISX11.9.
As it announced in August, Cummins now will rely on selective catalytic reduction on all its on-highway engines as an aftertreatment to neutralize NOx in the exhaust. Previously, Cummins had planned to use SCR only in its medium-duty engines and intended to rely solely on enhanced exhaust gas recirculation to deal with NOx in its heavy-duty engines.

At the top of the lineup is the Cummins ISX15, which the company said will offer improved performance and up to 5 percent better fuel economy than today’s ISX. Key features include the Cummins XPI high-pressure common-rail fuel system, an enhanced cooled-EGR system, a single VGT turbocharger and the Cummins Aftertreatment System that uses SCR and the diesel particulate filter.

Cummins will maintain ISX15 ratings from 400 hp to 600 hp, with torque outputs from 1,450 lb.-ft. to 2,050 lb.-ft. The engine initially will be available in Volvo, Kenworth and Peterbilt trucks, as well as the Freightliner Cascadia, said Lori Thompson, executive director of Cummins’ OEM business.

The ISX11.9 – which is aimed at vocational, day cab, regional and less-than-truckload linehaul applications, among others – shares numerous components with the ISX15, including cooled EGR, VGT turbocharger, XPI fuel system, electronic controls and the aftertreatment system. The ISX11.9 will be offered with ratings from 310 to 425 hp and torque from 1,150 to 1,650 lb.-ft.

One of the advantages of the 2010 lineup is improved fuel economy even when drivers aren’t as skilled or focused on driving for fuel efficiency, said Steve Charlton, vice president of heavy-duty engineering. “Our heavy-duty engines for 2010 have a large sweet spot due to the low-temperature NOx conversion capability of the copper-zeolite catalyst, which means that these engines are extraordinarily driver-friendly.”

Detroit’s new 15.6-liter slated for Western Star
The new Detroit Diesel DD16 engine will be in production for the Western Star 4900 series in March 2010 and the Western Star 6900 in July 2010, Western Star Trucks announced. Detroit Diesel said the DD16 is its most powerful engine and will be equipped with BlueTec emissions technology.

The DD16 displaces 15.6 liters and is suited for owner-operators, small fleets and specialty applications. The DD16 is the third in a series of heavy-duty engines from Detroit Diesel that covers three displacement categories: 13 liters, 15 liters and 16 liters.
David Siler, director of marketing for Detroit Diesel, said the DD16 will be offered with output and multitorque power ratings from 1,750 to 2,050 lb.-ft. torque and 475 to 600 hp.

Volvo, Mack promote SCR advantages
Volvo and Mack trucks equipped with engines that comply with tighter 2010 U.S. Environmental Protection Agency emissions regulations will have many advantages over current diesels, said spokesmen for the truck manufacturers.

One distinctive advantage Volvo claims is that its engines with selective catalytic reduction systems will not require active regeneration of diesel particulate filters during normal highway operating conditions, said Scott Kress, senior vice president of sales and marketing for Volvo. Kress said that thanks to the 2010 integration of Volvo’s SCR and DPF technologies, passive regeneration cycles will eliminate the need to inject diesel fuel into the DPF to oxidize accumulated soot.

“This, of course, results in reduced fuel consumption, reduced thermal cycling of expensive catalysts and lower overall operating costs,” he said. “It also relieves the driver of another responsibility – having to keep track of when an active regeneration needs to take place – and allows the truck to operate in areas where a recently cycled, and hot, DPF would be a safety hazard – indoors or in refineries, for example.”

Kress said the ability to passively regenerate DPFs depends on having the correct concentration of nitrogen oxides in the hot exhaust stream flowing into the unit’s filter. NOx enables passive regeneration, and SCR eliminates NOx from the exhaust after it flows through the DPF.

At a Mack press conference, Dave McKenna, director of powertrain sales and marketing, doused a lit candle with diesel exhaust fluid to prove that “DEF is not flammable.” The dramatic gesture was part of McKenna’s way of combating any concerns over the safety of SCR technology.

“SCR is simply the most viable and cost-effective way to meet EPA 2010,” McKenna said. “Other technologies, such as diesel NOx reduction systems, are unproven in engines with displacements larger than six liters, and diesel NOx absorbers have proven to be unviable. You can use massive EGR with EPA credits, but once those credits are gone, they are gone.”

McKenna said that based on a diesel fuel price of $2.42 a gallon, fleets can expect to save $1,655 a month on fuel by running Mack SCR diesel engines compared to pre-2010 engines. That figure includes the cost of DEF, he said.
- Linda Longton, John Baxter, Avery Vise and Jack Roberts contributed to this report

Comments are closed.

OverdriveOnline.com strives to maintain an open forum for reader opinions. Click here to read our comment policy.