Understanding demand in the new plug-in hybrid electric vehicle (PHEV) market is critical to designing more effective adoption policies. We use stated preference data from an innovative choice experiment to estimate demand for PHEVs relative to battery electric vehicles (BEVs) and to explore heterogeneity in demand for these vehicle technologies. We find that the gap between willingness to pay for PHEVs and their price premium over conventional vehicles is on the order of current subsidies, while that of BEVs is an order of magnitude larger. We also find evidence that consumers with access to HOV lanes are more likely to purchase PHEVs and that the characteristics of the home charging environment are more important for BEV purchase decisions. Finally, we use a latent class model to show that PHEVs draw an entirely new consumer segment into the electric vehicle market that would not consider purchasing a BEV.