Is Detroit’s DD15 engine the same as its Series 60? What you need to know

In 2007, the EPA announced that heavy-duty on-road diesel engines would have to meet much stricter emissions standards than in previous years. The new rules required a 55 percent reduction in NOx emissions and a 90 percent reduction in particulate emissions. The stricter emissions requirements forced many truck and on-road diesel engine manufacturers, including Detroit Diesel, to make modifications to their existing trucks and engines to meet emissions limits. Detroit was ahead of the time, having already equipped the 60 Series with exhaust gas recirculation technology during an earlier emissions rule change in 2002. The 60 Series’ EGR system recirculated some of the engine’s exhaust gases back into the intake manifold, reducing cylinder temperatures and NOx emissions. For the 2007 emissions regulations, the 60 Series also received a diesel particulate filter, which captured excess soot and other exhaust residues and burned them at high temperatures.

Unlike the 60 Series, which was updated to meet changing emissions requirements, the DD15 was developed to 2007 regulations. The strengthened common rail fuel system and turbo compound systems have done much to make the DD15 more compliant with the stricter regulations, and other changes have reduced its emissions levels even further. Like the 60 Series, the DD15 uses both exhaust gas recirculation and a diesel particulate filter. The DD15’s revised EGR system uses an integrated coolant manifold, reducing NOx emissions while improving fuel economy. The DD15’s DPF has also been upgraded with a new fuel injection system, allowing pollutants to be burned more effectively.