What does the DPF, with the aid of DEF, primarily reduce?

The DPF, or Diesel Particulate Filter, primarily works to reduce particulate matter in the exhaust of diesel engines. However, it operates in conjunction with DEF, or Diesel Exhaust Fluid, to achieve a reduction in nitrogen oxide (NOx) emissions. When DEF is injected into the exhaust stream, it reacts with NOx in a process known as Selective Catalytic Reduction (SCR). This reaction converts nitrogen oxides into nitrogen and water, significantly decreasing NOx emissions from the engine.

This combination of the DPF, which captures and stores soot from the exhaust, along with the use of DEF for NOx reduction, reflects a broader strategy for diesel emissions control, focusing on compliance with stringent environmental regulations regarding air quality and emissions. Therefore, recognizing the specific roles of DPF and DEF highlights the importance of managing nitrogen oxides in reducing the harmful emissions generated by diesel engines.