23 July 2002

Detroit Diesel Corporation (DDC) released more information about its 2002 Series 50 engine program. Beginning October 2002, the “pull-ahead” Series 50 engines utilizing exhaust gas recirculation (EGR) will meet the 2004 exhaust emissions standard of 2.5 g/bhp-hr NOx+NMHC.

The new emission control technologies include enhanced DDEC software for EGR control, a higher efficiency EGR cooler, steel pistons for improved durability, and new exhaust aftertreatment systems. Detroit Diesel first introduced EGR on the Series 50 engine in 2000. Since then, over 3000 Series 50 EGR engines have been produced. These newer technologies will provide up to a 90% reduction in particulate exhaust emissions and a 50% reduction in NOx emissions compared to engines produced in 1999.

A diesel oxidation catalyst will be used to meet the 0.05 g/bhp-hr particulate matter (PM) urban bus standard. In situations where “near zero” levels of particulate are desired, DDC’s Emitless particulate filter aftertreatment system will be available as a factory option in place of the catalyst. The Series 50 EGR engine with Emitless particulate filter and ultra-low sulfur fuel will achieve PM emissions of less than 0.01 g/bhp-hr, thus meeting the California urban bus regulations.

DDC originally released the Emitless particulate filter for urban bus retrofit in 2001 in cooperation with Engelhard. Since then, several hundred units have been placed in revenue service. Along with the Emitless particulate filter, DDC supplies an exhaust back-pressure sensor kit operated with DDEC IV software in order to facilitate filter maintenance and diagnostics.

According to DDC, fifteen Series 50 2.5g engines are already in revenue service in New York City, Las Vegas, and New Orleans experiencing operation in a wide range of duty cycles and environments. Ann Arbor Transit Authority (AATA) has their first Series 50 EGR-powered bus in revenue service and is now completing their first 2.5g EGR engine installation with a particulate filter. The AATA will be the first public transit fleet in the Midwest to run exclusively with Ultra Low Sulfur Fuel which, as in New York City, enables application of the Emitless particulate filter.

Source: DDC