UK fuel market today: supermarket gap at 4.0p 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 13 September 2026.
The structure of UK pump pricing holds its familiar shape today. Official government price data puts the supermarket discount for unleaded at 4.0p a litre against the branded-forecourt average, with diesel showing a 4.0p gap. Averaged across a 55-litre fill, the choice of forecourt type alone is worth £2.20.
The national average for unleaded at branded forecourts has moved up by 5.1p a litre over the past week.
At the top of the price ladder sit the motorway services, where unleaded carries a 20.9p-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, BT46 is the cheapest for unleaded at an average of £7.19 a gallon (158.1p a litre), while CA10 is the most expensive at £8.31/gal (182.9p). That 24.8p-a-litre spread is worth £13.64 on a 55-litre fill.
The cheapest supermarket unleaded recorded today: ASDA, Newtownards (BT23 4EU) at £7.03/gal (154.7p); TESCO, Bangor (BT19 1ND) at £7.04/gal (154.9p); TESCO, Bangor (BT19 7HB) at £7.04/gal (154.9p).
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 13 September 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.