Best day of the week to fill up
You might have heard “Tuesday is cheapest” or “avoid the weekend.” In reality, there is no magic weekday that stays true for every town or every month. Wholesale prices shift during the week, and each retailer chooses when to pass changes on.
Some patterns people notice: early-week adjustments after wholesale moves, or busier weekends when more people drive — but competition and local delivery schedules matter just as much.
What actually works: glance at live prices near you, and set My Alerts in the sidebar so you get an email when a station hits the rule you care about — without guessing the calendar.
Supermarket vs branded fuel — worth it?
Standard petrol (E10) and diesel sold legally in the UK must meet the same baseline quality rules, whether the pump says a supermarket or a big brand name. So you are not buying “illegal” fuel either way.
Where brands differ is often in additives, marketing, and premium grades (higher octane / different diesel formulations). Those may suit some engines or driving styles; for others the benefit is modest compared to simply paying less per litre.
Practical test: compare the fuel calculator for two forecourts on the same day, and track what you actually pay per tank over a month — that beats myths every time.
Why prices change daily
Pump prices are pushed and pulled by global oil, refining costs, exchange rates, and tax (duty and VAT). None of those sit still for long, so wholesalers update often.
On top of that, each forecourt competes with neighbours, runs promotions, and takes fuel deliveries on its own rhythm — so one corner can drop before another a mile away.
That is why yesterday’s “cheap” station is not guaranteed today. The stations map and trends pages are built around that idea: fresh, scoped data beats memory.
Turn hacks into habit on PetrolCompare
- Home — live board for your chosen area (UK-wide).
- Fuel calculator — tank size, £ per fill, £/mile, and side-by-side stations.
- Stations — map, filters, and saved “star” stations for alerts.
- My Alerts (sidebar) — email when your target or move rule is hit.