A plug-in, charge-depleting, parallel hybrid powertrain has been developed for a high performance sport utility vehicle. Based on the Ford U152 Explorer platform, implementation of the hybrid powertrain has resulted in an efficient, high performance vehicle with a 0-60 mph acceleration time of 7.5 seconds. A dual drive system allows for four-wheel drive capability while optimizing regenerative braking and minimizing electric motor cogging losses. Design of the system focused on reducing petroleum use, lowering greenhouse gas emissions, and reducing criteria tailpipe emissions. Additionally, this vehicle has been designed as a partial zero emissions vehicle (PZEV), allowing the driver to travel up to 50 miles in a zero emission all-electric mode. High-energy traction battery packs can be charged from the grid, yielding higher efficiencies and lower critical emissions, or maintained through the internal combustion engine (ICE) as with a traditional hybrid vehicle. The ICE is primarily used to provide average power and maintain state of charge (SOC). The ability to use the electric energy from the grid allows the most inexpensive way of driving the vehicle and reduces the dependence on petroleum. Electric power created at a large-scale power plant is produced more efficiently than by an ICE. However, to allow a long range and the option (rather than requirement) for using the plug, one has the capability to utilize liquid fuel through the ICE as well. Fuel consumption is reduced by more than 80% over the stock vehicle, resulting in average city usage of roughly 29 mpg (gasoline equivalent). Full functionality of the stock vehicle has been maintained, including four wheel drive, tow, and acceleration capabilities, as well as driver comfort, with no loss in cabin space and a small increase in vehicle weight. Analysis shows a final cost lower than comparable performance competitors. This paper details the design and implementation of this powertrain, and compares the hybrid vehicle response to that of the stock vehicle.