The usefulness, development, and implementation of a high-power starter/generator system for a series–parallel 232 HEV are demonstrated in this article. Simulation and experimental results verify and demonstrate the performance of the starter/generator subsystem in different operating modes. The high-power density of the starter/generator and a well-designed torque controller enabled fast cranking of a diesel engine; a shortened cranking time helps to reduce the engine vibrations during starting. The 1.9-L diesel engine started in 250 ms helps to reduce the tailpipe emissions. The operation of the diesel engine and the starter/generator at their highest efficiency points for power generation in the series mode with start and stop cycling improves the fuel efficiency and reduces emissions for typical urban driving. The starter/generator is also available for adding the torque to the engine by operating in the motoring mode during peak acceleration demands.