Every M4 motorway services in Great Britain, cheapest diesel first, with the cheapest worthwhile station a short drive off the motorway.
The cheapest M4 motorway diesel in Great Britain right now is
199.9p
at J49 M4 Motorway, Llanedi.
Motorway services average 217.9p,
18.3p a litre more than the GB average of
199.6p: about
£9.17 more on a 50-litre fill.
At 9 of these services there is a cheaper station within 3 miles that is worth the extra miles. It is shown in green under each one.
Prices last refreshed at 3:26pm on 24 October 2026, from the official UK Government Fuel Finder scheme. Averages exclude Northern Ireland, which is shown separately below.
Our free journey planner shows the cheapest fuel along your whole route, and its Skip the Motorway Services card picks out the cheaper stations near the services you will pass.
How much more do motorway services charge for fuel?
Right now motorway services in Great Britain charge an average of 217.9p a litre for diesel, which is 18.3p more than the average of 199.6p across all GB forecourts. On a 50-litre fill that is about £9.17 extra.
Which motorway services has the cheapest fuel?
The cheapest motorway services for diesel in Great Britain right now is J49 M4 Motorway, Llanedi on the M4 at 199.9p. Prices change through the day, so the list above is always the up-to-date answer.
Is it worth leaving the motorway to buy fuel?
Often, yes. Next to each services we show the cheapest station within 3 miles that has an up-to-date price and should be open now, and only when it still saves at least £1 on a 50-litre fill after the extra miles there and back (counted at 40 mpg). Distances are in a straight line, so check the station is close to a junction you can use. Leaving and rejoining also adds time, and some junctions only let you off in one direction.
Why is fuel dearer at motorway services?
Motorway services are open around the clock, pay for large sites with parking, toilets and food, and drivers on the motorway have little choice of where to stop. Those costs and the lack of nearby competition are why their prices are higher.
How do you decide which stations are motorway services?
We start with the motorway services flag in the UK Government Fuel Finder data. Some retailers set that flag wrongly, so a flagged station is only listed when its name or address also names a motorway or a services area. A few services that are not flagged are added when they are run by a services operator such as Moto, Welcome Break, Roadchef or Extra.
How often are motorway fuel prices updated?
We refresh the data every 15 minutes from the UK Government Fuel Finder scheme. Each station shows when its price was last reported, and prices more than a week old are moved to the end of the list.
40 of the 168 stations marked as motorway services in the government data are not listed, because their name and address do not name a motorway or a services area. Spot a services that is missing or wrong? Let us know.
