Thailand, Southeast Asia’s leading automotive hub, is undergoing a structural transition from internal combustion engine vehicles to electric vehicles (EVs), driven by domestic industrial upgrading ambitions and global decarbonization pressures. While this shift is expected to support long-term growth and sustain export competitiveness, its short-run macroeconomic implications remain underexamined. This working paper empirically assesses the automotive sector’s contribution to GDP growth, using a composite activity index and interaction terms capturing the EV transition period.