Officials of Mack Trucks, Inc. and Volvo Trucks North America announced Wednesday that they will use engine technology based on exhaust gas recirculation (EGR) to meet new federal diesel engine emissions regulations scheduled to take effect in 2007.
The company also confirmed that its EPA '07 solution would include a diesel particulate filter (DPF) system to achieve reductions in particulate matter called for in the new regulations.
The announcement ends speculation about which system the company would employ in North America. The other major choice Selective Catalytic Reduction, SCR, is becoming the standard in Europe.
Cummins, Caterpillar and International have already made known their intentions to use various forms of EGR systems for North American markets. Many in the industry were eagerly awaiting Mack’s decision.
“We haven’t abandoned SCR research in Europe,” a Mack spokesperson said. “EGR is the best solution for North America when you look at the total picture. We have not closed the door on SCR. One day it may be viable for North America.”
In a prepared statement, Mack president and CEO Paul Vikner said: "Mack ASET engines have been in customer trucks since early 2002, and that means no other engine manufacturer has more experience with EGR than we do.” The U.S. Environmental Protection Agency has made it clear that it wants any emission control system to operate at least 150,000 miles without maintenance. SCR needs to replenish the urea solution, vital to its operation, about every 5,000; EPA officials have said publicly this aspect concerns them. Because engines can still run without the urea, EPA worries that drivers will not replenish it on schedule – because of cost and inconvenience - thereby defeating the purpose of the emission system.
It is also unclear if fuel stops can or will stock urea in large enough quantities to meet a potential demand.
However, there still may be a place for SCR systems in North America, because the 2010 limit on NOx can not be met by current EGR systems alone.