Nowadays, the effects of pollution at a global scale are mainly due to the emissions of greenhouse gases (CO₂ in particular), especially generated by thermoelectrical plants, as well as the transport, industrial, and civil sectors. Moreover, local pollution effects are generated by several pollutants, such as CO, NO_x, SO_x, VOC, and PM, produced during combustion in transports or building thermal plants. Because of the increasing demand for mobility at an urban scale, pollution caused by transportation plays a significant role. To reduce its environmental impact, a partial or total replacement of old and polluting vehicles with more ecological ones must be urgently implemented. With this aim, in the paper, a detailed analysis of the vehicle fleet of the city of Reggio Calabria (Italy), with reference to passenger cars has been carried out, elaborating four scenarios to reduce their pollutant emissions from 2017 to 2025, both greenhouse gases and local scale ones, through the replacement of old and polluting vehicles with hybrid or electric ones.