INTRODUCTION Electrified vehicles are a fast growing and very relevant component of the automotive marketplace. Worldwide vehicle sales are projected to be on pace for significant growth for the remainder of this decade and several decades to come [ 1,2]. In addition, the global car parc, a measure of the number of vehicles in use, is on pace to grow from about one billion vehicles today to approximately 2.0 billion vehicle in 2035 [ 3]. With these trends, the energy consumption and emissions implications of these vehicles is greatly important to future economic and environmental situations. Both of these items can be improved by effectively using electricity as a mobile energy source on a portion of these vehicles. Many analysts agree that electrified vehicle growth is expected to outpace the growth of car sales by a significant amount [ 3,4]. From a societal perspective, electrified vehicles that use grid energy instead of petroleum are desirable because they diversify the primary energy sources used for transportation. This has positive implications on energy security for nations, CO2 generation (depending on fuel used to generate electricity), and more centralized treatment of other criteria emissions.1 Additionally, electrified vehicles are seen by consumers as having highly desirable attributes, like operating cost, but report that usefulness and acquisition costs limit attractiveness [ 5]. Ultimately, the effectiveness of electrification depends on the pace of adoption, which will hinge on development and deployment of technologies that simultaneously improve the customer utility of the vehicles and the costs to acquire and operate them. Many automotive OEMs and the extended supply bases are engaged to tackle this challenge. To date, there are a variety of electrified vehicle types that 1. In this paper the term criteria emissions is used to refer to CO, NOx, HC, and Particulate Matter.have been studied, developed, produced, and sold. In this paper we focus on two types, the Plug-in Hybrid Electric Vehicle (PHEV) and the Extended-Range Electric Vehicle (E-REV). A PHEV has been defined by the SAE [ 6] as “A hybrid vehicle with the ability to store and use off-board electrical energy in the RESS (rechargeable energy storage system).” An E-REV has been defined [7] as “A vehicle that functions as full-performance battery electric vehicle when energy is available from an onboard RESS and having an auxiliary energy supply that is only engaged when the RESS energy is not available”. In that prior publication, PHEVs and EREVs were largely conceptual and projections were made comparing their respective attributes, especially energy consumption and emissions [7]. These were based purely upon simulation of prototypical vehicle attributes projected over some aggregate commute driving schedules. At this point in time, sufficient production examples and quantities of both PHEVs and E-REVs have been sold such that a real world assessment of their effectiveness at driving electrically can now be compared to prior predictions. The Chevrolet V olt has been produced since 2010 and is largely the prototypical E-REV that was examined in the 2008 paper [ 7]. There are a few competitor PHEVs that have subsequently been put into production in 2011, 2012, and 2014. They vary in capability but are representative of PHEVs having attributes previously described as “conversion PHEVs” or “urban capable” PHEVs. This paper will compare them in their ability to increase all-electric driving, reduce petroleum consumption, and eliminate initial engine starts (i.e. “cold starts”) and associated criteria emissions. Lastly, it will explore the avenues for improvement in E-REVs beyond the current Chevrolet V olt and discuss the relative benefits of improved electric range and extended range driving efficiency on the energy consumption and emissions in the real world.Chevrolet Volt Electric Utilization A