Plug-in hybrid electric vehicles (PHEVs) offer the potential to reduce oil imports, greenhouse gases, and fuel costs, but high upfront costs discourage many potential purchasers. Making an economic comparison with conventional alternatives is complicated in part by sensitivity to drive patterns, vehicle range, available energy management, and charge strategies that affect battery wear and gasoline consumption. Identifying justifiable battery replacement schedules adds further complexity to the issue. The National Renewable Energy Laboratory developed the Battery Ownership Model to address these and related questions. The Battery Ownership Model is applied here to examine the sensitivity of PHEV economics to drive patterns, vehicle range, available energy management, and charge strategies when a high-fidelity battery degradation model and financially justified battery replacement schedules are employed. We find that energy management methodology, all-electric range, maximum beginning-of-life state of charge, and basic charge timing generally have a small impact on the total cost of ownership of PHEVs; however, PHEV economics do prove sensitive to drive patterns and the availability of an at-work charger.