Rising fuel prices can hamper economic activities in urban and regional areas. Despite following a mean reverting pattern over time, the spread between retail and wholesale prices of petrol exhibits significant differences across various geographical locations in Australia. Using a hierarchical cluster analysis, this paper classifies 109 retail locations into six heterogeneous groups with homogeneous contents. By identifying the whereabouts of those petrol stations that set relatively high gross profit margins within each comparable cluster, this study can provide important policy implications for both consumers and regulators. Contrary to popular belief, we found that excessively high margins are not necessarily observed only in remote and rural areas.