PHEV engine operational considerations for criteria emissions control and low fuel consumption

As one part of a large research program in plug-in hybrid-electric vehicles (PHEVs), Argonne National Laboratory has tested many conventional, hybrid-electric and plug-in hybrid-electric vehicles. Data were examined from several low-volume after market PHEVs. Found in the study were trade-offs between minimizing emissions and reducing fuel consumption (by using more electrical propulsion). Key to successful emissions control is how the engine is operated during initial start, warm-up, and restart. Temperature management for engine restart is also important. Some data from charge-sustaining operation are contrasted with the charge-depleting results. The challenges in describing blended-PHEV fuel consumption are explored. This paper will examine the interesting challenges unique to blended-type PHEVs, illustrated with test data from several test vehicles.