2010 Engine Update: Cummins' Big Switch
September 2008 Commercial Carrier Journal 63 D iesel engine manufacturers had been gearing up for a fight over 2010 engine emis-sions technology for North America. On one side were proprietary engine makers Detroit Diesel, Volvo, Mack and newcomer Paccar, which planned to use selective catalytic reduction (SCR) an exhaust after-treatment that uses a urea-based liq-uid to neutralize oxides of nitrogen. On the other side were big bore engine newcomer Navistar, with its proprietary MaxxForce engine, and Cummins the largest on-highway heavy-duty engine supplier in North America. Cummins and Navistar would rely on high-pressure fuel injection systems and enhancements to exhaust gas recirculation (EGR) technology, avoiding the need for after-treatment hardware or the purchase of diesel emissions fluid (DEF). The only wild-card question was answered in June when Caterpillar announced that it would forego a 2010 heavy-duty on-highway engine and instead focus its resources on off-high-way engines in North America, on-and off-highway engines elsewhere in the world and a planned venture to market a Cat-branded severe service truck built by Navistar. (See Cat's out of the bag, , July 2008.) Cat's decision, coupled with Freightliner's announced plans to add Cummins in heavy-duty trucks, means Cummins is the lone non-captive heavy-duty engine supplier to on-highway truck owners. And everyone other than Mack and International would offer both SCR and EGR-only solutions. So everything was settled until Aug. 13. That was the day that Cummins changed the dynamics substantially by abruptly announc-ing that it now would add SCR to its engine offering. Any lingering doubts regarding SCR apparently vanished in an instant. As of now, Navistar probably the most vocal manufac-turer pushing a non-SCR approach stands alone in pursuing an EGR-only emissions solution for 2010. Fuel for thought SCR supporters have been tout-ing fuel economy benefits of their approach. By using an aftertreatment to transform NOx in exhaust into nitrogen and water vapor, the engine itself can be allowed to run more efficiently, they noted. Of course, pur-chasing and managing DEF as well as maintaining the aftertreatment device itself were factors to consider. But as the price of diesel fuel neared $5 a gal-lon and remains in the $4 range, the fuel economy improvements began to look more attractive. In its announcement, Cummins conceded that SCR allowed for fuel economy improvements. Cummins Emission Solutions, a provider of SCR systems, will supply integrated exhaust aftertreatment systems for Cummins heavy-duty and midrange engines. (Cummins already had planned to use CUMMINS ' BIG SWITCH BY AVERY VISE & JACK ROBERTS Leading diesel engine maker goes with SCR after all Cummins' initial heavy-duty emissions strategy for 2010 was to rely solely on exhaust gas recirculation (EGR). Based on data on new aftertreatment mate-rials, however, the engine maker said last month that it would add selective catalytic reduction (SCR) in a bid to improve fuel economy.