1. Measure between comparable tank levels
Suggested full-to-full method: start with a full tank and record the odometer. At the next full refill, record the new reading and the litres added. Follow the normal safe filling procedure; do not overfill to force a round number.
If there are partial fills in between, include all of them plus the final refill. Exclude the initial fill: it establishes the starting fuel level. Missing receipts or different end levels make the interval unreliable.
2. Calculate consumption and cost
Distance = ending odometer − starting odometer. L/100 km = litres used ÷ distance × 100. Fuel cost per kilometre = the cost of those litres ÷ distance.
Illustrative example: the odometer moves from 40,000 to 40,600 km and the full-to-full interval uses 72 litres costing KSh 12,960. Consumption is 12 L/100 km and fuel cost is KSh 21.60/km. These figures are examples, not fleet targets.
| Measure | Calculation | Example result |
|---|---|---|
| Distance | 40,600 − 40,000 | 600 km |
| Consumption | 72 ÷ 600 × 100 | 12 L/100 km |
| Fuel cost | 12,960 ÷ 600 | KSh 21.60/km |
3. Investigate changes in context
DOE/EPA guidance identifies load, terrain, idling and maintenance among the factors affecting fuel economy. A rise in fuel use alone is not proof of theft.
Our suggested review starts with odometer errors and missing fills, then checks route, load and maintenance records. Compare several similar intervals. For stationary equipment, use an appropriate runtime measure such as litres per engine hour instead of kilometres.
Sources & further reading
Sources reviewed . Worked examples and suggested workflows are Phuel Card editorial guidance.