The continuous increase in global CO2 emissions, together with more stringent vehicle emissions and fuel economy regulations around the world require innovative solutions and technologies to address these challenges. To this end, Connected and Automated Vehicles (CAV) are one pathway by which significant fuel economy improvements and emissions reductions may be simultaneously achieved. In this study, the potential fuel economy improvements stemming from improved driving behaviors, as well as dedicated engine rightsizing possible with CAVs have been considered. The study has focused on two different powertrain configurations: a conventional gasoline engine driven powertrain, and a hybrid electric vehicle. Simulations were performed in GT-Suite for a model year 2019 Jeep Compass with a baseline 2.4 L I4 engine on three different driving schedules: the FTP75, the US06 and a real world driving cycle.