Road transport is responsible for 76% of cargo movement in South Africa; at the same time transport cost in SubSahara Africa forms a much higher fraction of the total cost of landed goods compared to the rest of the world. Fuel represents the single biggest operational cost for road transport operators; efforts towards improved fuel efficiency are therefore a priority within this sector. As fuel usage depends on many factors, including engine size, vehicle fabrication, driver behaviour, payload, traffic conditions and route inclinations, it is not a trivial exercise to create accurate consumption benchmarks for a specific operation. This paper investigates various factors that are known to impact fuel utilization with the aim of quantifying the relative importance of the contribution of each. Fuel usage data was collected for a representative set of trucks covering all major routes in South Africa and for various cargo categories over a 3 year period. This data was filtered based on different criteria, including driver identity, route and vehicle model. Comparisons were drawn between consumption figures derived from manually recorded refuel events and figures derived from measurements that are automatically performed by on-board vehicle sensors. It was concluded that driver behaviour and the possible siphoning of fuel from vehicles seem to be a major factor and would justify further actions towards curbing fuel losses. At the same time route inclination, payload and vehicle model also play an important role and should be incorporated into costing models used to determine how different routes and trips are priced.