Where drivers pay least for fuel this week: the 3.9p supermarket gap
By Anthony Sharkey, Chief Operating Officer, New Reg Limited · 30 Jul 2026
Official price data this week: supermarkets undercut branded forecourts by 3.9p a litre on unleaded, and the postcode you fill up in matters as much as the brand.
Supermarket forecourts are selling unleaded for 3.9p a litre less than branded forecourts on average this week, official government price data shows. On a 55-litre tank that is a saving of £2.15 simply by choosing where you fill up, and the diesel gap is 5.0p a litre.
The national average for unleaded at branded forecourts has moved up by 3.7p a litre over the past week.
Motorway services remain the most expensive place to fill up: unleaded there averages 17.4p a litre more than at ordinary branded forecourts, £9.57 extra on a full tank. Where possible, fill up before you join the motorway.
The postcode divide remains real. Across postcode districts with at least five forecourts reporting, OL6 is the cheapest for unleaded at an average of 149.9p a litre, while CA10 is the most expensive at 173.3p. That 23.4p spread is worth £12.87 on a 55-litre fill.
The cheapest supermarket unleaded recorded this week: COSTCO WHOLESALE, Leicester (LE4 8PH) at 144.9p; COSTCO WHOLESALE, Leeds (LS10 1BG) at 146.9p; TESCO, Belfast (BT8 6PZ) at 146.9p.
Prices are drawn from the official government fuel price feed, which most UK forecourts now update through the day. Use the live search on this site to compare every forecourt near you before you drive.
**Disclaimer.** All figures are computed directly from official UK government fuel price data (Open Government Licence v3.0), as published by fuel.co.uk, and were correct when this bulletin was prepared. Pump prices change through the day and may differ by the time you read this. Averages describe groups of forecourts, not every site within a group. This is general information, not financial or consumer advice.