Live prices
Cheapest petrol and diesel prices in Carmarthen
7 forecourts tracked in Carmarthen (7 reporting unleaded (E10), 7 reporting diesel (B7), 5 reporting premium (E5), 3 reporting super diesel). Prices last refreshed at 12:02am on 20 September 2026.
The cheapest reported unleaded petrol (E10) in Carmarthen is £7.59 a gallon (166.9p per litre) at Murco, Derwydd Garage, Cynwyl Elfed, Carmarthen, SA33 6TP, Carmarthen. The average across 7 forecourts currently reporting this grade is £7.74 a gallon (170.3p per litre), so choosing the cheapest rather than an average-priced forecourt saves about £1.70 on a 50-litre fill. That local average is 2.2p per litre below the UK average of 172.5p.
The average has risen 0.3p per litre since yesterday. The average has risen 3.0p per litre since last week.
Prices last refreshed at 12:02am on 20 September 2026, supplied through the official UK Government fuel price open data scheme and checked every 30 minutes.
At 166.9p per litre, the cheapest unleaded in Carmarthen is the highest we have recorded here in 4 weeks. The Carmarthen average has risen 2.9p a litre over the past week. 2 forecourts in Carmarthen have changed their unleaded price today.
Unleaded Prices
Unleaded (E10)
- Highest
- £7.81/gal171.9p/L
- Average
- £7.74/gal170.3p/L
- Lowest
- £7.59/gal166.9p/L
Diesel Prices
Diesel (B7)
- Highest
- £8.86/gal194.9p/L
- Average
- £8.84/gal194.5p/L
- Lowest
- £8.77/gal192.9p/L
Premium Unleaded Prices
Premium Unleaded (E5)
- Highest
- £8.11/gal178.5p/L
- Average
- £8.35/gal183.7p/L
- Lowest
- £8.11/gal178.5p/L
Super Diesel Prices
Super Diesel (SDV)
- Highest
- £9.16/gal201.5p/L
- Average
- £9.44/gal207.6p/L
- Lowest
- £9.16/gal201.5p/L
All forecourts in Carmarthen
7 forecourts in Carmarthen, with live prices and full addresses. Showing 1 to 7.
Derwydd Garage, Cynwyl Elfed, Carmarthen, SA33 6TP, Carmarthen · SA33 6TP
Usually cheapest midnight to 5am, priciest 5pm to 10pm here
DirectionsDiesel B7
Premium E5
C K's Supermarket, Old ST. Clears Road, Johnstown, Carmarthen · SA31 3HL
Usually cheapest midnight to 5am, priciest 1pm to 6pm here
DirectionsDiesel B7
Tanerdy Garage, Tanerdy, Carmarthen · SA31 2EY
Usually cheapest 8am to 10am, priciest 1pm to 6pm here
DirectionsDiesel B7
Premium E5
Super Diesel
Diesel B7
Premium E5
Gwalia Garage, Rhydargaeau, Carmarthen · SA32 7DR
Usually cheapest 4am to 9am, priciest 5pm to 10pm here
DirectionsDiesel B7
Premium E5
Super Diesel
Lysonnen Road, Carmarthen, Carmarthen, Carmarthenshire · SA33 5DT
Usually cheapest midnight to 5am, priciest 4pm to 9pm here
DirectionsDiesel B7
Premium E5
Super Diesel
A40, Carmarthen, Carmarthen · SA32 7EN
Usually cheapest midnight to 5am, priciest 5pm to 10pm here
DirectionsDiesel B7
Search near Carmarthen
Ask the fuel analyst
Answers come straight from recorded official price data, refreshed every 30 minutes.
Cheapest reported unleaded
Murco
Derwydd Garage, Cynwyl Elfed, Carmarthen, SA33 6TP, Carmarthen
166.9p/L
Cheapest reported diesel
Murco
C K's Supermarket, Old ST. Clears Road, Johnstown, Carmarthen
192.9p/L
By fuel grade in Carmarthen
Nearby areas
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Prices are sourced from official UK government fuel-price data (Open Government Licence v3.0). Updated every 30 minutes.
Questions about fuel prices in Carmarthen
- What is the average petrol price in Carmarthen?
- The average unleaded (E10) petrol price in Carmarthen is currently 170.3p per litre (approx. £7.74/gal), based on live data from 7 forecourts reporting this grade. Prices are updated every 30 minutes from official UK government data.
- What is the average diesel price in Carmarthen?
- The average diesel (B7) price in Carmarthen is currently 194.5p per litre (approx. £8.84/gal). This is based on live data from forecourts in the area, updated every 30 minutes.
- Which is the cheapest petrol station in Carmarthen?
- Murco at Derwydd Garage, Cynwyl Elfed, Carmarthen, SA33 6TP, Carmarthen currently has the cheapest reported unleaded petrol in Carmarthen at 166.9p per litre (approx. £7.59/gal). Prices change regularly, so check this page for the latest.
- Which is the most expensive petrol station in Carmarthen?
- According to official UK government fuel price data, Asda White Mill Express Petrol (SA32 7EN) currently has the highest reported unleaded (E10) price in Carmarthen at 174.9p per litre (approx. £7.95/gal). Prices are refreshed every 30 minutes, so this can change through the day.
- How do I find the cheapest fuel near Carmarthen?
- Use the search box above to enter your postcode. fuel.co.uk will show you every forecourt ranked cheapest first, with live prices updated every 30 minutes from the GOV.UK Fuel Finder.