Utility factor frameworks for plug-in hybrid electric vehicles: A comparative assessment
比较了不同效用因子框架对插电式混合动力汽车能耗和排放评估的影响，发现现有欧盟因子可能低估瑞士的电动行驶比例，建议采用区域校准的因子以提高评估准确性。
• New Swiss- and segment-specific Utility Factors derived from mobility data. • Vehicle size class systematically shifts achievable UFs and outcomes. • Regulatory UFs strongly shape PHEV energy use and emissions results. • Current EU UF may underestimate electric driving shares in Switzerland. • Region-, vehicle- and ownership-calibrated UFs improve environmental assessments. The environmental performance of Plug-in Hybrid Electric Vehicles (PHEVs) strongly depends on user behavior. Utility Factors (UF), used in regulatory assessments, estimate electric driving shares but fail to capture regional patterns or individual variability. This study compares the former European UF, the revised 2025 version, and new Swiss- and segment-specific UFs derived from national mobility data. These factors are applied to emissions and energy use data from eight PHEVs tested on a chassis dynamometer under different cycles and temperatures, and results are benchmarked against On Board Fuel Consumption Monitoring (OBFCM) data. Findings show that the choice of UF significantly affects estimated fuel use, electric demand, and emissions, with the new European UF potentially underestimating electric driving in Swiss conditions. Differences across vehicles and test conditions highlight the need for regionally calibrated UFs for accurate environmental evaluations and suggest that current regulatory approaches may misrepresent real-world PHEV performance.