Impact of Range Extender Engine Configuration on Powertrain Performance and Vehicle Integration

The light-duty transportation sector is experiencing a worldwide push towards reduced carbon intensity. One pathway that has been developed focuses on replacing internal combustion engine (ICE)-based vehicles with full-electric battery electric vehicles (BEV), which offer local carbon dioxide (CO₂)-free mobility. However, batteries offer a limited mobility range and can require long recharging times, leading to a limited range perception among some vehicle operators. A range-extended electric vehicle (REEV) utilizes a small ICE to mitigate the range concerns of BEVs, while also enabling a battery size reduction with its associated improvements in cost, weight, and manufacturing-related CO₂ intensity. A previous study by the authors discussed evaluation criteria for range extender engines (REx) and compared additive technology options to enable cost-, efficiency, or power-optimized REEV applications using a modular approach. This study contrasts the dedicated REx with associated modular additive technology packages against a commercially available ICE vehicle and a BEV. This study furthermore investigates the impact of REx configurations on vehicle powertrain parameters, including battery sizing, total system cost, energy split, and combined vehicle range. A range extender powertrain was found to offer a total cost of ownership (TCO) benefit compared to conventional ICE powertrains and offers significant vehicle weight advantages over current high-range BEVs. A cost-optimized REx was found to be optimal for low-power drive cycles and those with high percentages of electric driving. The high-efficiency REx offered a cost advantage for high-power drive cycles, long daily commutes, or where battery recharging infrastructure is limited.