Influence of test cycle and fuel property on fuel consumption and exhaust emissions of a heavy-duty diesel engine

Highlights: • Impacts of test cycle and fuel type on diesel engine emissions were investigated. • Test cycle, fuel, and their interaction explained >84% of variance in emissions. • PM, CO, and NOx emissions were slightly lower in biodiesel blend than fossil diesel. • Fuel consumption, PM and gas emissions were significantly higher under ETC than ESC. • Higher PAHs in fuels produced more heavy molecular weight PM-bound PAH emission. In this study, dynamometer engine tests were conducted to investigate the impact of test cycle and fuel type on fuel consumption and exhaust emissions of a heavy-duty diesel engine. This study presented novel approaches by utilizing comprehensive statistical analysis to assess these impacts on particulate matter (PM), PM-bound polycyclic aromatic hydrocarbons (PAHs), and multiple gaseous pollutants. Four types of fuels—two conventional diesels (X and Y) and each with 5% blend of biodiesel—were used under European Transient Cycle (ETC) and European Stationary Cycle (ESC). There were statistically significant higher fuel consumption and emission rates (by 9–73%) under ETC than ESC due to more occurrences of lower engine speeds and loads under ESC, and X fuels had higher emission rates of PM and carbon dioxides ([CO₂]; 2.1–13%) but lower rates of hydrocarbons ([THC]; 44%) attributed to higher cetane number, sulfur contents and boiling points. Compared with conventional diesel, biodiesel blend had slightly lower emission rates of PM, CO, and NO_X (1.7–6.6%) but higher fuel consumption (1%) and CO₂ and THC emission rates (0.9–2.1%). The results of this study contributed to the limited datasets on the interactive effects of test cycle with fuel property on diesel vehicle exhaust emissions.