The lowest station price is only half the answer
Most fuel searches start with a simple question: where is the cheapest petrol or diesel near me? That is useful, but it can still send a driver to a station that costs more once the trip is counted.
Route & Fuel is built around a more practical question: is that cheaper station still worth driving to?
The UK Fuel Finder scheme requires registered motor fuel traders to submit price updates within 30 minutes of a change. The guidance also warns that third-party displays can lag, so drivers should still check when the price last changed before buying. Current prices are useful, but the route and extra drive still matter.
What can wipe out the saving?
- Extra distance: a station that is cheap but far away can use more fuel than it saves.
- Extra time: a small saving may not be worth a long delay.
- Your vehicle: MPG, tank size and fuel type change the real result.
- Your route: a station just off your route may be better than a cheaper one in the wrong direction.
- Stop-start traffic: congestion can turn a short detour into a wasteful one because repeated braking and acceleration increases fuel use.
The better comparison
The useful result is not simply “lowest price”. It is the stop where price, route and MPG details still leave you better off.
A quick worked example
Imagine Station A is on your route at 149.9p per litre. Station B is 144.9p per litre but adds a four-mile round trip. If you plan to buy 45 litres, the headline saving is 5p × 45 = £2.25.
If your car averages 40mpg on that detour, four extra miles uses roughly 0.45 litres. At around 145p per litre, that detour fuel is about 65p. Your saving after extra driving falls from £2.25 to about £1.60 before you even value the extra time.
That does not mean the cheaper station is wrong. It means the right answer depends on the fill amount, the route shape and how efficient your vehicle is in real driving.
When the detour is usually worth it
- You are filling a larger amount: a 4p saving matters more on 55 litres than on 15 litres.
- The station is already on your route: a small price difference can be worthwhile when the detour cost is nearly zero.
- You need that stop anyway: toilets, a shop, air, water or a motorway break can make the same stop solve more than one problem.
- The price difference is unusually large: large gaps can survive a small detour, but only if the route still makes sense.
When it is probably not worth it
- The fill is small: saving 3p per litre on 15 litres is only 45p before detour cost.
- The road is slow or congested: official efficiency advice from the Vehicle Certification Agency and Energy Saving Trust both emphasises smoother driving and avoiding unnecessary braking or acceleration.
- You would drive past a fair-priced station anyway: a slightly dearer stop on the route can beat a cheaper stop in the wrong direction.
- The price may have changed: listed station prices are useful, but the station price remains the final source before purchase.
Where the app helps
Route & Fuel keeps the saving calculation close to the map and station result. That makes it easier to compare the fuel saving before committing to the stop.
The app is designed to join the pieces a driver normally has to estimate mentally: latest UK fuel prices, journey direction, your MPG, fill-up amount and station details. Preview prices here; use the app for journey saving checks, MPG estimates, alerts, fill-up history and Google Maps directions.