This paper investigates the share of household travel electrified or Utility Factor(UF) and well-to-wheel(WtW) greenhouse gas(GHG) emissions of battery electric vehicles(BEVs) in two-car households. We examine a multiyear travel data collected via GPS loggers from both vehicles(internal combustion engine vehicle-ICE and BEV) belonging to 73 California households:30 Nissan Leaf, 21 Chevy Bolt, and 22 Tesla ModelS.

Results indicate that two distinct substitution patterns moderated by vehicle attributes effectuate diversified outcomes on UF and GHG. Energy efficiency losses due to technology and user preferences counteracts range enabled UF gains offsetting BEV’s GHG benefits. Fuel inefficient ICEs could aggravate emissions of longer-range BEV households. Conversely, energy efficiency improvements can augment GHG reduction, but UF decreases.

Maximum UF of 75–80% can be achieved by upgrading to a longer-range BEV. Longer-range performance-oriented BEV upgrade does not improve UF but nullifies 15–30% of emission abatement potential realized by driving their existing BEV instead of ICE.

Key words: Battery electric vehicles, Driving and charging behavior, Electric vehicle miles traveled, Gasoline displacement, Household preferences, Utility factor