Is it worth driving further for cheaper fuel?
A lower price across town is tempting, but the fuel you burn getting there can quietly eat the saving. Here is the simple maths of when a detour pays off, and when the pump round the corner was cheaper all along.
The trap of the cheaper sign
A station a few kilometres away is advertising fuel for noticeably less, so off you go. What the sign does not show is the cost of the trip: every extra kilometre there and back burns fuel you have to pay for, plus your time. Sometimes the detour still wins. Often it does not, and you feel clever while quietly losing money.
The simple sum
How far the cheaper pump can be before it stops being cheaper
Break-even detour for a 40-litre fill, a car doing 7.0 L/100 km, and fuel at about 2.20 € a litre. The distance counts both ways.
Fillz. The typical gap is the median we measured between the cheapest station in a city and the typical one.
Two numbers decide it. The saving is the price gap per litre times how many litres you are buying. The cost of the detour is the extra distance, there and back, times your consumption, times the fuel price. If the saving is bigger than the detour cost, go. If not, stay.
Say a station is 20 cents a litre cheaper and you are filling 40 litres: that is 8 in savings. Now suppose it is 6 km further, so 12 km round trip, in a car using about 7 litres per 100 km at 1.80 a litre: the detour burns roughly 0.84 litres, about 1.50. Here the detour clearly pays. Shrink the gap to 5 cents, or push the distance to 20 km, and the sums flip.
What tips the balance
How much you are filling. A big fill multiplies the saving, so a detour that fails on a splash of fuel can pay on a full tank.
The size of the price gap and your distance. A wide gap close by almost always wins; a small gap far away almost never does. Traffic and your own time count too, even if they do not show up in litres.
You do not have to do the sum
Nobody wants to run a calculation at every junction. That is the whole point of Fillz: it takes the price, the distance and your consumption, does exactly this maths on every station around you, and highlights the one that genuinely leaves the most in your pocket, detour included. We call it worth the detour.
Common questions
How far is too far for a cheaper station?
It depends on the price gap and how much you are buying, not on a fixed distance. A big gap and a full tank justify a longer trip; a small gap rarely justifies any detour at all.
Does my car's consumption really matter?
Yes. A thirsty car spends more fuel on the same detour, so the same trip needs a bigger saving to be worth it. Fillz uses your consumption in the calculation.
What about my time?
Time and traffic are real costs the fuel maths ignores. If a detour only just pays on paper, the minutes lost often mean the nearer pump was the better call.
Let the app do the arithmetic
Cheaper is not always cheaper for you. Fillz counts the detour on every station around you and shows the one that actually pays off, so you never chase a saving that the drive already spent.
Open Fillz