Diesel Prices in Swansea
Today's cheapest diesel across Swansea and South Wales, ranked pence per litre.
Diesel prices across Swansea are not one number — they are hundreds of them. On any given day the gap between the cheapest and most expensive diesel pump in the SA postcode area regularly exceeds 10p per litre, which is £5 or more on a single 50-litre fill.
This page tracks diesel only. fuelfinder.ai lists every Swansea forecourt that reports to the UK Government's CMA Pump Watch open-data scheme, ranks them by diesel pence-per-litre, and shows how recently each price was confirmed. Standard UK diesel is B7 — up to 7% biodiesel, meeting the BS EN 590 standard whether you buy it from a supermarket or a branded forecourt.
If you want petrol prices as well, the Swansea fuel prices hub covers both grades side by side. If you only ever put diesel in the tank, this is the faster page — search a SA postcode and the cheapest diesel near you is at the top of the list.
How It Works
- Step 1: Enter a Swansea postcode — Any SA postcode, or share your location for instant results.
- Step 2: Compare diesel only — Every nearby forecourt's B7 diesel price, cheapest first, with the last-updated time.
- Step 3: Fill up for less — Tap through for directions to the cheapest diesel pump on your route.
Why Drivers Use fuelfinder.ai
- diesel focused — Ranked on B7 diesel alone — no averaging across grades that don't go in your tank.
- South Wales coverage — Every Swansea forecourt in the CMA feed, plus surrounding South Wales sites.
- Always free — No account, no app download, no paywall on prices.
- Built for the road — Loads fast on mobile so you can check before you commit to a forecourt.
Frequently Asked Questions
Where is the cheapest diesel in Swansea today?
It changes daily. Supermarket forecourts — Asda, Tesco, Sainsbury's, Morrisons and Costco where present — usually lead on diesel in Swansea, typically 5–10p below the branded majors. Search your postcode above for today's actual ranking rather than relying on a rule of thumb.
How much does diesel cost in Swansea right now?
The live table on this page shows the current cheapest, median and most expensive diesel price reported across Swansea. Figures come from the CMA Pump Watch feed and refresh twice daily, so they reflect what retailers have officially declared.
What grade of diesel do Swansea stations sell?
Standard UK diesel is B7 — up to 7% biodiesel, meeting the BS EN 590 standard whether you buy it from a supermarket or a branded forecourt.
Is premium diesel worth it in Swansea?
Premium diesel adds detergent and cetane-improving additives. It costs roughly 10–15p per litre more and is rarely worth it for ordinary commuting.
Why is diesel cheaper in some parts of Swansea?
Local competition is the biggest factor. Where two supermarkets sit within a mile of each other, both price aggressively. Sites with no nearby rival — city-centre forecourts, or stations on a single-approach road — have no pressure to match, and Swansea pump prices reflect that.
How often is Swansea diesel price data updated?
Retailers submit to the CMA scheme through the day and fuelfinder.ai refreshes twice daily. Each station row shows its own last-updated time, so you can see whether a price is hours or days old before you drive to it.