Officials of Mack Trucks and Volvo Trucks North America announced Wednesday that they will use engine technology based on exhaust gas recirculation (EGR) to meet the stricter federal diesel engine emissions regulations scheduled to take effect in 2007.
The companies also confirmed that their emissions solutions will include a diesel particulate filter system to achieve reductions in particulate matter required by the '07 regulations.
The announcement ends speculation about which system the OEMs would use in North America. The other major choice, Selective Catalytic Reduction (SCR) is becoming the standard in Europe.
“EGR is the best solution for North America when you look at the total picture,” said a Mack spokesperson. “We have not closed the door on SCR. One day it may be viable for North America.”
Cummins, Caterpillar and International had already made known their intentions to use various forms of EGR systems for North American markets.
EPA has made it clear that it wants any emission control system to operate for at least 150,000 miles without maintenance.
The SCR system relies on a urea solution that must be replenished every 5,000 miles, and EPA officials have said publicly that this concerns them. Because engines can still run without the urea, EPA worries that for cost or convenience drivers will not replenish it on schedule, thus compromising emissions reduction.
It is also unclear whether fuel stations can or will stock urea in large enough quantities to meet potential demand.