Analysis of plug-in hybrid electric vehicles efficiency by plug-in electric hybrid factor (Pihef)

Since plug-in hybrid electric vehicles (PHEVs) are becoming commercially available, several questions arise about their efficiency, range and emissions. PHEVs can be evaluated according to various classifications and recently, an additional approach, named Plug-In Hybrid Electric Factor (Pihef) has been introduced. This paper contributes an analysis of PHEV efficiency, taking into account Pihef, followed by a discussion on Pihef definition. At the end, key performance of popular PHEVs is compared according to different regulations applied in the European Union and the USA.