This study presents a comparative life cycle assessment (LCA) of greenhouse gas (GHG) emissions from three common passenger vehicle types: Battery Electric Vehicles (BEVs), Hybrid Electric Vehicles (HEVs), and Internal Combustion Engine Vehicles (ICEVs). The analysis investigates how national electricity grid compositions influence total emissions across production, use, and end-of-life phases over a 240,000 km vehicle lifetime. Representative models—Tesla Model Y (BEV), Toyota RAV4 Hybrid (HEV), and Volkswagen Tiguan 2.0 TSI (ICEV)—are evaluated in the contexts of Norway, Germany, and Poland, along with a theoretical high-carbon grid scenario (HCS). Results indicate that BEVs offer the lowest life cycle emissions in low-carbon electricity systems such as Norway’s, but may exceed HEV or ICEV emissions in carbon-intensive regions like Poland or HCS. These findings underscore the critical importance of aligning electric mobility strategies with power sector decarbonization efforts.