Search this question and you will find confident claims that fuel is cheapest on a Tuesday, or first thing Monday, or the last day of the month. Most of that folklore is imported from countries like Australia, where regulated price cycles genuinely exist. Britain doesn’t work that way — and our price data, refreshed continuously across 8,000+ stations, shows what actually happens.
What UK prices really do
- There is no reliable weekly cycle. UK retailers reprice in response to wholesale costs and local competitors, not the calendar. Days-of-the-week patterns that appear in one month dissolve the next.
- Supermarkets lead, others follow. A supermarket price cut typically ripples through nearby stations within days — the practical rhythm is competitive, not weekly.
- “Rockets and feathers” is real. Prices climb within days of a wholesale jump but drift down for weeks after a fall. The best time to fill up is therefore early in a falling market and late in a rising one — which you can only know by watching, not by picking a weekday.
Timing versus location: no contest
Suppose perfect timing saved you 2p/L — a generous estimate for the UK. The spread between the cheapest and dearest station in a typical town is 8–12p/L on the same day (see today’s spread). Choosing the right forecourt beats choosing the right day by a factor of five. Location first, timing second, folklore never.
A realistic routine
- Fill up when your tank hits a quarter, at the cheapest station on your normal routes — two taps to find it.
- If headlines say oil has spiked, fill sooner rather than later; pump prices will follow within days.
- If oil has fallen, patience pays — but check who locally has cut first, because someone always leads.