Impact of ethanol-gasoline implementation on regulated and unregulated emissions from Euro 3-5 standard vehicles over the WLTP driving cycle.

Tailpipe emissions are the primary contributors to unhealthy air quality worldwide. However, few studies have comprehensively investigated the VOC and regulated pollutant emissions from mobile sources. To address this, three in-use vehicles representing Euro 3 to 5 standards fueled by gasoline/bioethanol blends (E3 and E10) were tested. The vehicles operate under WLTP, which is considered closer to real-world driving. When ethanol was added to gasoline, the Euro 5 vehicle, as expected, exhibited the lowest emission levels, aligning with the more restrictive Euro 5 standard. It is noteworthy that there is a significant reduction of VOCs in both (E3) and (E10). The main components of VOCs for both Euro 4 and 5 vehicles are aromatic compounds, of which benzene, toluene, and xylene are the most abundant species. The average reduction for E3 and E10 were observed to be 6.64% and 63.8% for benzene, 8.02% and 35.3% for toluene, and 9.89% and -15.4% for xylene, respectively, in comparison with G0. The OFPs were 11.3 and 9.30 mg ozone/km for the Euro 4 and 5 vehicles, respectively, when fueled by G0. The average reduction in OFP compared to G0 was estimated at 43.3% for Euro 4 and 13.4% for Euro 5 vehicles. Alkenes were the main OFP species, followed by aromatics, alkanes, ketones, and aldehydes for both Euro 4 and 5 vehicles. The findings here are valuable for policymakers developing strategies to reduce the health impact of tailpipe emissions.