Achieving transport decarbonization depends on electric vehicle (EV) and fuel cell vehicle (FCV) deployment, yet their material demands and impacts vary by vehicle type. This study explores how powertrain preferences in light-duty vehicles (LDVs) and heavy-duty vehicles (HDVs) shape future resource use and material-related environmental outcomes. Using dynamic material flow analysis and prospective life cycle assessment, we assess three scenarios. In the S3 EV-dominant scenario, 2050 lithium and cobalt demand rises by up to 11.9-fold and 1.8-fold relative to 2020, with higher global warming and human toxicity impacts. The S2 FCV-dominant scenario leads to a 21.7-fold increase in platinum-group metal demand, driving up freshwater ecotoxicity and particulate emissions. A balanced S1 scenario, EVs in LDVs and FCVs in HDVs, yields moderate material demand and environmental burdens. These findings demonstrate that no single pathway can fully resolve material-related impacts, while combining EVs and FCVs across LDVs and HDVs enables a more balanced and sustainable transition.