UK fuel market today: supermarket gap at 3.4p a litre
By Anthony Sharkey, Chief Operating Officer, New Reg Limited
Promo's daily reading of official forecourt price data: the supermarket discount, the motorway premium and the postcode divide, all in one bulletin, taken on 26 August 2026.
The structure of UK pump pricing holds its familiar shape today. Official government price data puts the supermarket discount for unleaded at 3.4p a litre against the branded-forecourt average, with diesel showing a 4.9p gap. Averaged across a 55-litre fill, the choice of forecourt type alone is worth £1.87.
The national average for unleaded at branded forecourts has moved up by 0.6p a litre over the past week.
At the top of the price ladder sit the motorway services, where unleaded carries a 20.1p-a-litre premium over the ordinary branded average. The captive-audience premium is one of the most persistent features of the UK fuel market.
The postcode divide remains real. Across postcode districts with at least five forecourts reporting, BT15 is the cheapest for unleaded at an average of 151.9p a litre, while CA10 is the most expensive at 176.6p. That 24.7p spread is worth £13.59 on a 55-litre fill.
The cheapest supermarket unleaded recorded today: TESCO, Banbridge (BT32 4LF) at 148.9p; SAINSBURY'S, Aylesbury (HP19 8EH) at 148.9p; TESCO, Banbridge (BT32 4AX) at 148.9p.
These figures come from the government fuel price feed, refreshed through the day for thousands of forecourts, and are tracked continuously by Promo as part of its fuel market record.
Figures taken on 26 August 2026. All figures are computed directly from official UK government fuel price data (Open Government Licence v3.0), as published by fuel.co.uk. This page is refreshed with the latest prices, so the figures above are those of the date shown, not of the date it first appeared. 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.