Several diesel passenger car boosting systems were studied to assess their impact on vehicle performance and fuel economy. A baseline 1.5L diesel engine model with a single VGT turbocharger was obtained through Gamma Technologies' fast running model library. This model was modified to explore multiple two stage boosting systems to represent the anticipated architecture of future engines. A series sequential turbocharged configuration and a series turbocharger-supercharger configuration were evaluated. The torque curves were increased from that of the original engine model to take advantage of the increased performance offered by two stage boosting. The peak cylinder pressure for all models was limited to 180 bar.Drive cycle analysis over the WLTP was performed using these engine architectures, while assessing the sensitivity to various system parameters. These parameters include: vehicle weight and aerodynamic drag, EGR target maps, level of downspeeding, and turbocharger inertia. Vehicle performance and fuel economy was evaluated for the different boosting configurations to determine which vehicle design characteristics are complimented by the individual boosting configurations, and which are hindered. The simulation results demonstrate that the turbocharger-supercharger configuration provides benefits in both fuel economy and performance for all of the vehicle parameter variations studied. Specific trends between these benefits and each of the varied vehicle system parameters are presented as well.