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October 1, 2007 7:50 AM, EDT

Cummins Taps EGR for 2010 Engines

OEM Spurns Urea System for Class 8 Engines

By Frederick Kiel, Staff Reporter
This story appears in the Oct. 1 print edition of Transport Topics.

NASHVILLE, Tenn. — Cummins Inc. said it will not use selective catalytic reduction for its 2010 heavy-duty engines, making it the first manufacturer to reject the urea-based system widely used in Europe to cut emissions.
Cummins doesn’t believe longhaul fleets, “with their irregular routes, would benefit from SCR, which requires the addition of urea at set intervals, which may be difficult to find on . . . long-distance trips,” said Steve Charlton, executive director of heavy-duty engineering at Cummins.
Volvo Powertrain, which makes engines for Volvo and Mack, and Freightliner subsidiary Detroit Diesel Corp., both have said they will use SCR to meet the Environmental Protection Agency’s 2010 emissions rule. That regulation will require the elimination of  almost all nitrogen oxides and particulate matter from engine exhaust.
Caterpillar Inc. and International have not said if they will use SCR to meet 2010 emissions levels.
“We researched all possibilities and concluded that the best choice for our customers was to use an upgraded version of our ’07 powertrain,” Charlton said in a Sept. 23 press conference here.
He said Cummins’ 2010 engines will not use a NOx filter and that the soot filter “will be the same one we are installing this year.”
Ed Pence, general manager of the Columbus, Ind., firm’s heavy-duty engine business, said Cummins will introduce two new heavy-duty platforms in its “X” series in 2010 — 11.9-liter and 16-liter models, in addition to its standard 15-liter system.
Pence said Cummins would stop selling its ISM engine in North America in 2010 but would continue manufacturing it for export at its Jamestown, N.Y., plant.
Cummins said it expected to gain a market advantage by avoiding new technology for its 2010 engines, and some industry sources agreed.
“If Cummins can meet 2010 EPA emission standards using improved 2007 technologies . . . then they would have a competitive advantage in the marketplace,” Chris Brady, president of Commercial Motor Vehicle Consulting, told Transport Topics.
Most new European trucks already use SCR to cut NOx emissions, and Cummins said it would use SCR for its 2010 medium-duty engines.
“Most medium-duty truck drivers run local routes and are at home most nights,” said Jeff Weikert, executive director of mid-range engineering at Cummins. “They will be able to find a steady source of urea in their vicinity, so that SCR is the best choice for customers in that weight range.”
Ensuring an adequate supply of urea has been a concern in the industry since SCR emerged as the most likely technology to meet the new standards. EPA said that manufacturers using SCR to meet 2010 standards must demonstrate there is a viable national distribution network for urea, which is injected into the exhaust stream to reduce emissions. (4-2, p. 1)
“Selective catalytic reduction systems work by chemically reducing NOx to nitrogen,” Johnson Matthey, a Malvern, Pa., producer of catalysts to control pollution emissions, said on its Web site. “It is necessary to add a reductant to the system to enable this reaction,” which is usually urea.
Charlton said Cummins’ 2010 heavy-duty engines will look almost the same as its ’07 models. The only new technology will be the addition of a high-pressure common-rail fuel-injection system designed and built by the company’s Cummins-Scania joint venture.
The new fuel-injection system “generates better performance and cleaner exhaust by maintaining high injection pressures, regardless of engine speed a-cross the entire rpm range,” Charlton said.
Cummins also plans to reduce the ratio of air to fuel for 2010. “By taking more air out of the system, that will send lower volumes of oxygen to mix with the diesel, which means the fuel that is burned will be at a much higher concentration that will burn away NOx and diesel particulates at a much better rate than ’07 engines,” Charlton said.
Allen Schaeffer, executive director of the nonprofit Diesel Technology Forum, told TT that “Cummins’ decision bodes well, not just for Cummins but for the whole industry, if they can produce a 2010 engine with proven technology, which should mean lower costs to customers.”
He said that Cummins’ an-nouncement was “a positive indication overall that the OEMs understand the need to get knowledge of their 2010 systems out to their customers as soon as possible.”
Schaeffer said he did not believe truck manufacturers would have difficulty putting two different powertrain technologies into their trucks.
Roy Wiley, spokesman for International Truck & Engine Corp., agreed. “We already have two types of engines in our heavy trucks,” Cummins and Caterpillar, Wiley said. “Next year, we will add a third — our own Maxx-Force,” which he said would be available in 2008.
The new engine is a modified version of one produced in Europe by MAN; the two companies have said they also have had discussions about producing a joint SCR-based engine for 2010.