To save on a fill-up, compare the total cost: price per litre multiplied by your planned volume, plus detour fuel and any extra charges. The station with the lowest displayed price is not always the best stop for your journey.
1. Compare the same fuel
Start with fuel compatible with your vehicle. Comparing E85 with SP95-E10 does not directly measure your saving: these fuels are not interchangeable for every vehicle.
In Fillzz, select your fuel and explore stations relevant to your planned journey. The map adds context: which side of the road is the station on, and what route is actually needed to reach it?
2. Use your planned fill-up volume
A price difference makes more sense when applied to the volume you intend to buy. The formula is: gross saving = volume × price difference per litre.
| Volume purchased | Price difference | Saving before detour |
|---|---|---|
| 20 litres | €0.05/L | €1.00 |
| 40 litres | €0.10/L | €4.00 |
| 50 litres | €0.15/L | €7.50 |
These are calculation examples, not observed station prices. Use the amount you actually expect to buy rather than your tank’s full capacity if it is not empty.
3. Subtract the extra journey cost
A lower price is not enough if reaching the station requires a costly detour. Count every kilometre added to the journey you would have made anyway, including the return or route needed to rejoin your original journey.
On 40 litres with a €0.10/L difference, the gross saving is €4. With 10 extra kilometres, consumption of 6 L/100 km and fuel at €1.80/L, the detour uses 0.6 litres costing €1.08. That leaves €2.92 before other costs.
Try your own numbers in the detour calculator.
4. Check that the stop is practical
Before starting navigation, check available details: opening hours, access, services and the price update time. Fillzz refreshes data every 10 minutes. Its availability and freshness depend on the information supplied by data providers: a listed station does not necessarily have a price for every fuel it sells.
The price may change before you arrive. Always confirm the amount shown at the pump. Tolls, waiting or your available time may also affect your decision; they are not included in the detour’s fuel cost alone.
5. Make it a simple habit
Compare before a journey you already plan to make. Identify one or two stations that fit your route, calculate the cost if the detour is significant, then prepare navigation while safely parked.
See how to compare stations in Fillzz or plan your next fuel stop.
Method and limits
Examples are calculated from the values shown in this guide. They are not a promise of savings or a report of current prices. Actual consumption depends on your vehicle and journey conditions. Learn about the data shown in Fillzz.