Cleaner diesel

Automotive Design & Production, August, 2004

As diesel engine makers scramble to figure out the least expensive ways to meet upcoming Tier 2 emissions regulations, International Truck and Engine Corp. (Warrenville, IL) has hit on a novel approach: use the technology developed by the regulators themselves. International has formed a partnership with the Environmental Protection Agency (EPA) to evaluate a new low-emission technology called "Clean Diesel Combustion" that uses in-cylinder control of nitrogen oxides (Nox) instead of relying on aftertreatment devices to clean the NOx out of the exhaust stream.

Originally developed at the EPA's National Vehicle and Fuel Emissions Laboratory in Ann Arbor, MI, the technology combines improvements in fuel injection, air management, turbocharging, and combustion in an attempt to achieve a low-cost way to reach 2007 light-duty and 2010 heavy-duty Tier 2 standards. Specifically, the technology adds an hydraulically intensified fuel system to reduce particulate and smoke emissions; a boost system that produces more complete fuel combustion; and a low-pressure exhaust gas recirculation device that lowers peak combustion temperature and consequently the formation of NOx. International will begin its evaluation with a light-duty V6 as the test engine.--KEW