5 June 2000
Detroit Diesel Corporation (DDC) delivered its first Series 50 EGR engine to Pace, the suburban bus division of the Regional Transportation Authority in Arlington Heights, IL. The new Series 50 bus engine features both exhaust gas recirculation (EGR) and variable nozzle turbocharger technology (VNT). EGR and VNT are both controlled by Detroit Diesel Electronic Controls (DDEC).
According to Pat Scully, Vice President of Bus & Coach Sales for Detroit Diesel, “DDC is the first major heavy-duty engine manufacturer to offer EGR and VNT on a high volume production engine. EGR systems have been refined over the years as a result of their wide spread use in the automotive industry. Detroit Diesel has been supplying automotive diesel engines equipped with EGR since 1991. Detroit Diesel has had Series 50 field units in service since mid-1999 accumulating over 500,000 test miles and will deliver over 7,500 Series 50 engines to the Bus market in advance of October 2002.”
To meet bus engine emissions standards, DDC chose to combine the Series 50 engine platform and DDEC IV, with EGR, with the addition of VNT. There are other approaches to meet the new emissions standards, such as simply retarding engine timing. However, retarded timing alone without other technology results in a noticeable loss of fuel economy and acceleration. DDC said, by using EGR and VNT, controlled by DDEC, it was able to achieve the best package of performance, economy, and low emissions.