The transportation sector significantly contributes to global greenhouse gas (GHG) emissions, prompting interest in sustainable mobility. Individual car purchase preferences also reflect environmental concerns and the need for sustainable mobility. This study uses life cycle assessment to compare the environmental impacts of four car purchasing options: new and second-hand battery electric vehicles (BEV) and internal combustion engine vehicles (ICEV). Results show that second-hand vehicles, especially Euro 6d_full compliant ICEVs and BEVs, often outperform new ones environmentally due to avoided production emissions. A new BEV could surpass a new ICEV in GHG emission performance after some driving distance, but never outperforms a second-hand BEV within a typical lifespan. The carbon intensity of electricity generation greatly affects BEV sustainability, with high-emission regions limiting their benefits. The study challenges the assumption that new BEVs are always the greenest choice and emphasises the value of extending vehicle lifespans and tailoring recommendations to local contexts.