Cheapest fuel on your route
Tell us where you are driving. We price every forecourt along the way and rank them by what they actually cost — pump price plus the fuel the detour burns — rather than by the number on the sign.
Why the sign price is the wrong number
Every fuel comparison shows you the pump price. On a journey that is not the number that matters, because reaching a forecourt costs fuel too, and the further off your route it sits the more of the saving it eats. A forecourt three pence cheaper is not three pence cheaper if it is four miles of extra driving away.
The arithmetic is simple enough to do in your head once you have seen it. An out-and-back detour of d miles in a car doing m miles per gallon burns 2d ÷ m gallons — about 4.5d/m litres. Spread that across the litres you are buying and you have the real premium. At 45 mpg with a 55-litre fill, every mile off route costs roughly 0.2% of the pump price — so a two-mile detour needs to save you about 0.7p a litre just to break even.
That is what the ranking above does for every forecourt on your route. The full working is in this guide, and the calculator does the same sum for a single journey.
What this changes on a long drive
Motorway services are the default fuel stop on any long journey, and they are the most expensive fuel in the country: £1.90 against £1.71 elsewhere, a premium of 18.6p a litre or £10.23 a tank. They are chosen not because they are good value but because stopping there requires no decision. Deciding in advance is worth several pounds every long trip, and the whole decision takes one search.
It also changes which forecourt you aim for. The cheapest on a route is rarely the first one you pass, and it is often a supermarket a mile from a junction rather than anything visible from the road. See what motorway services charge, or compare the chains to know which signs are worth looking for.
Common questions
How does the route fuel search work?
You give a start and a destination. We plot the driving route, find every forecourt within your chosen detour of that line — 8,081 UK forecourts are in the search — and rank them not by the price on the sign but by what the fuel actually costs you once the drive to reach it is paid for.
What is the difference between the pump price and the "true cost"?
A forecourt two miles off your route is four miles of driving there and back. In a 45 mpg car that is about 0.4 litres of fuel, spread across whatever you put in the tank. On a 55-litre fill that adds roughly 0.7% to the price — so a forecourt 3p cheaper but four miles off route is really about 1.8p cheaper. The ranking does that arithmetic for every forecourt on the route so you do not have to.
Should I fill up before a long journey or on the way?
On the way, but not at the services. Motorway forecourts average 18.6p a litre above the national median — £10.23 on a tank — and they are the default choice precisely because they need no planning. A forecourt a mile off a junction almost always beats them, and this tool finds it before you set off.
Does it account for my car?
Yes — mpg and tank size are both adjustable, and both change the ranking. A thirsty car pays more for the same detour, so the tool weights distance more heavily; a small tank spreads the detour cost over fewer litres, which does the same. The defaults are 45 mpg and 55 litres, roughly a mid-size family car.
How current are the prices?
They come from the government Fuel Finder scheme, which since February 2026 has required every UK forecourt to report a price change within thirty minutes of it taking effect. We re-read that feed through the day.