Abstract:

Plug-in hybrid electric vehicles (PHEVs), which combine an electric and a conventional combustion engine drive train, offer the potential to reduce global greenhouse gas (GHG) emissions and local air pollution if they drive mainly on electricity. However, there is limited evidence on how much driving PHEVs actually do on electricity and how much conventional fuel they use in real-world operation. This report provides an analysis of real-world usage and fuel consumption of approximately 100,000 PHEVs in China, Europe, and North America. Findings of this analysis are: (1) PHEV fuel consumption and tail-pipe CO2 emissions in real-world driving, on average, are approximately two to four times higher than type-approval values. (2) The real-world share of electric driving for PHEVs, on average, is about half the share considered in the type-approval values. (3) PHEVs electrify many kilometers per year. (4) Decreasing combustion engine power while increasing all-electric range and frequency of charging improve real-world fuel consumption and CO2 emissions of PHEVs.