Northern Ireland fuel prices: the same tank can cost nearly £10 more depending on where you fill up

Where you stop for fuel in Northern Ireland can make a much bigger difference than most drivers realise. The Consumer Council's town-by-town fuel-price data for 10 September 2026 shows a 16p-per-litre gap in average petrol prices and an 18p-per-litre gap in average diesel prices between the cheapest and most expensive town averages in the survey.

For a 55-litre fill, that is roughly £8.80 difference on petrol and £9.90 on diesel before you have changed car, driving style or route. It is simply the difference between where the fuel is bought.

Dungannon was cheapest in the 10 September snapshot

In the Consumer Council's 10 September archive, Dungannon had an average petrol price of 152.9p per litre and average diesel of 169.9p. At the other end of the petrol table, Newry averaged 168.9p. For diesel, Irvinestown averaged 187.9p.

Those are town averages, not a promise that every forecourt in that town was charging the same amount. In several places the Consumer Council recorded a sizeable gap between the lowest and highest individual prices as well.

Prices were already moving quickly

The week-on-week movement was noticeable. On 3 September, the same Consumer Council archive implied an NI petrol average of about 154.3p per litre and a diesel average of about 175.0p. By 10 September, the figures embedded in the town comparisons point to roughly 157.1p for petrol and 177.9p for diesel.

That is an increase of around 2.8p per litre for petrol and 2.9p for diesel in a week. On a 55-litre fill, that change alone adds approximately £1.54 to a petrol tank or £1.60 to a diesel one.

Why town averages can be so different

Retail fuel prices are influenced by wholesale costs, local competition, delivery costs, forecourt strategy and how quickly each retailer changes pump prices after its own fuel costs move. A town with several aggressively priced forecourts can look very different from an area with fewer alternatives.

That is why the useful comparison is not 'petrol versus diesel' in isolation. A driver should also compare the forecourts along journeys they already make. Driving 25 miles purely to save 3p per litre can easily wipe out the saving; filling up at a cheaper station that sits on your normal commute is different.

Fuel price matters when choosing a used car too

A cheaper purchase price can hide a more expensive ownership pattern if the car uses much more fuel than the alternative. The calculation is especially important for drivers doing high annual mileage.

For example, the difference between a car averaging 35mpg and one averaging 50mpg is far more significant over 15,000 miles than it is for someone doing 4,000 miles around town. Fuel type, engine size and real-world economy should be considered alongside insurance, tax, servicing and depreciation.

You can browse used cars for sale on PureCar and compare fuel type, gearbox, price and mileage before deciding what suits your driving.

The practical way to use the Consumer Council data

• Check the current NI fuel-price checker before a long journey or expensive fill.
• Compare stations on a route you already use rather than making a special trip that burns the saving.
• Look at the lowest local price, not only the town average.
• If you drive a lot, track your actual litres and miles for a few tanks rather than relying entirely on the dashboard economy figure.

The 10 September snapshot shows why this is worth doing. Northern Ireland is small, but pump prices can still vary enough across towns to put nearly a tenner between two full tanks of the same size.