The Impact of Isobutanol and Ethanol on Gasoline Fuel Properties and Black Carbon Emissions from Two Light-Duty Gasoline Vehicles

This study reported black carbon (BC) mass and solid particle number emissions from a gasoline direct injection (GDI) vehicle and a port fuel injection (PFI) vehicle on splash blended E10 and iB16 fuels over the FTP-75 and US06 drive cycles at standard and cold ambient temperatures. For the FTP-75 drive cycle, the GDI vehicle had lower solid particle number and BC mass emissions from E10 (5.1×10¹² particles/mile; 4.2 mg/mile) and iB16 (5.2×10¹² particles/mile; 3.9 mg/mile) compared to E0 (7.2×10¹² particles/mile; 7.0 mg/mi). Most of the reductions were attributed to the statistically significant reductions during the phases 1 and 2 of the FTP-75 drive cycle. iB16 was also observed to have statistically significant reduction on BC emissions when compared to E0 at cold ambient temperature but E10 did not show such BC reduction. For the PFI vehicle, most of the solid particle number and BC mass emissions were emitted primarily during phase 1 of the FTP-75 drive cycle. In general, solid particle number and BC mass emissions from the warmed PFI vehicle were low (0.5-1.3×10¹² particles/mile; 0.2-0.8 mg/mi) and most of the fuel effects were not statistically significant. However, iB16 fuel was consistently observed to increase both solid particle number and BC mass emissions during phase 1 of the FTP-75 drive cycle while no statistically different solid particle number and BC mass emissions were observed for the E10 fuel.