Electric vehicles (EVs) are promoted as ‘clean’ technologies and offer promising reductions in transportation emissions. Nevertheless, their environmental benefits critically depend on the local electricity grid mix and the type of emission being considered. Here, we conduct a comparative life cycle assessment (LCA) of the four dominant light-duty vehicles (LDVs) categories at both the global scale and across three prominent countries leading the global EV market – Norway, the US, and China – each with a distinct electricity grid mix. By analyzing different environmental indicators, specifically emphasizing global warming potential and respiratory effects, and quantifying related parametric uncertainties (e.g. fuel economy, electric driving share and vehicle lifetime mileage), we reveal that the EV advantages vary across these regions and across different types of environmental impacts. Our results support stakeholders in finding the most environmentally friendly vehicle and policy interventions while considering multiple factors, emphasizing tailored approaches over one-size-fits-all solutions in sustainable transportation.