The formula
Fuel cost = distance ÷ efficiency × fuel price, with efficiency in kilometres per litre.
Example
A 350 km drive in a car that does 14 km per litre needs 25 litres. At 1.60 a litre, the fuel costs 40.00.
Converting your car’s figure
Cars are often rated in litres per 100 km. Divide 100 by that number to get km per litre. A car using 7 L/100 km does about 14.3 km per litre.
Make the estimate realistic
- Use your real-world figure, not the brochure number
- Add the return trip
- Expect higher use in heavy traffic, with roof racks or with a full load
Ways to spend less
- Keep tyres properly inflated
- Drive at steady speeds
- Remove unused weight and roof boxes
- Share the trip and the cost