This paper presents the development of an energy management strategy of a Plug-in Hybrid Electric Vehicle (PHEV). In this case, a rule-based optimal controller selects the appropriate operation mode. Furthermore, advantages and drawbacks of such vehicles are compared with respect to other vehicles powered by the most popular powertrain architectures. Simulations are carried out for three predefined drive cycles repeated over different geographic regions with varying CO2 intensities. The results reveal that the proposed controller is able to switch the vehicle’s operating mode according to previous established criteria.