Make the numbers work for your journey
Is cheaper fuel worth the detour?
A lower pump price only saves money if the saving on your fill-up exceeds the cost of the extra driving. Work out both before choosing a station.
Your fill-up, your numbers
Check the detour cost
The starting values are an illustrative example, not current station prices. Change them to match your trip.
Worked example
About £1.91 left after extra fuel
- Saving at the pump
- £2.50
- Extra driving fuel
- £0.59
- Estimated extra fuel used
- 0.40 litres
The pump saving covers about 17.1 total extra miles on these assumptions.
Your time, wear, tolls, membership fees and other costs are excluded. A small fuel saving may not justify the journey.
Count only the driving you add
If the alternative station adds two miles on the way there and two miles on the way back, enter four extra miles. If you already pass it, enter only the diversion from your planned route. The distance to a pin on a map is not necessarily the road detour.
How the calculation works
- Pump saving: litres bought × price difference in pence ÷ 100.
- Extra fuel: total extra miles ÷ UK MPG × 4.54609 litres per imperial gallon.
- Driving cost: extra litres × alternative price in pence ÷ 100.
- Estimated saving: pump saving minus extra driving fuel cost.
Both options assume you buy the same number of litres. Extra fuel is valued at the alternative station's price. This is a simple fuel-cost estimate; it does not calculate a road route or model changes in driving conditions.
Check the comparison before setting off
Use the same fuel grade at both stations, check their price report times, and allow for access or opening restrictions. Your actual economy can differ from the figure you enter. The price shown at the pump is the final check before filling.
Compare reported prices on Fuel Finder, then use your own figures here. Saved stations and price alerts can help you follow the stops you use regularly; see account and alert options.