Australian cities have seen continued growth in private car travel that has resulted in increasing vehicle energy consumption and greenhouse gas emissions. While much research has shown that vehicle demand is related to urban spatial structure, very little research has investigated the spatial patterns of private vehicle fuel efficiency (VFE) and its association with socio-spatial circumstances in urban areas. This study has combined State-level motor vehicle registration datasets with standard vehicle efficiency measures that permit a comprehensive understanding of spatial variation of VFE in urban areas. A spatial-based technique was applied to explore intra-urban patterns in socio-spatial conditions of private vehicle efficiency in Brisbane and Sydney. In both cities, the VFE of the private vehicle fleet tends to be lower in outer suburbs than in middle and inner suburbs. The analysis further shows that by linking the standard vehicle efficiency measures to the entire urban fleet datasets the VFE outcome showed a moderate relationship to socio-spatial variables in both cities. The built environment and household economic status are more transferable factors that relate to the VFE across different urban contexts. Outcomes from this research are of relevance to policy makers charged with identifying highly oil-vulnerable communities and designing intervention strategies to improve household vehicle efficiency.