Fuel prices fall in August after two months of rises but drivers continue to pay over the odds at the pumps

3 September 2025

Average pump prices fell by less than a penny in August ending two months of rises, new analysis by RAC Fuel Watch has found.

The average cost of a litre of unleaded petrol dropped by just 0.39p in the month, from 135.03p at the start to 134.64p on 31 August, with diesel down by 0.72p, from 142.92p to 142.2p at the end of the month.

Supermarket price reductions were similarly slight, with the average price of unleaded down 0.23p in August, from 131.49p to 131.26p, and diesel down 0.3p, from 139.11p to 138.81p.

Drivers can today expect to pay £74.05 on average to fully fill a family-sized 55-litre car, with those at supermarkets paying £72.19 – around £2 less a tank. The corresponding costs for a diesel car are £78.21 on average, and £76.35 at supermarkets.

Although oil prices, and therefore wholesale fuel prices, barely budged in August the RAC believes drivers are still paying more than they should at the pumps. This is a point echoed by the Competition and Markets Authority (CMA) which stated earlier in the summer that the margin on fuel remains high, and that ‘overall competition in the UK’s road fuel retail market remains weak.’** The relatively high prices drivers face are all the more frustrating given they are meant to be benefiting from a 5p-per-litre fuel duty cut.

Despite average fuel prices being higher than they perhaps ought to be, RAC analysis of forecourt data has uncovered some of the cheaper sites drivers can aim for*** – something drivers can do themselves using the Fuel Finder tool within the free myRAC mobile app –available to all drivers, whether current RAC members or not:

Unleaded petrol (UK average 134.6p/litre)

126.7p – MFG Morrisons in Leighton Buzzard, Bedfordshire
126.9p – BP on Cottingham Road in Corby, Northants
126.9p – BP on Newton Road in Bovey Tracey, Devon
126.9p – BP on New Islington Road in Liverpool

Diesel (UK average 142.2p/litre)

131.9p – BP on Newton Road in Bovey Tracey, Devon
134.7p – MFG Morrisons on Amy Johnson Way in Blackpool, Lancs
134.7p – MFG Morrisons on Green Oaks Way in Widnes, Cheshire
134.9p – BP on New Islington Road in Liverpool

Pump prices charged in Northern Ireland also point to what’s possible, given retailers are paying the same price to buy wholesale fuel as those elsewhere. Drivers there pay on average just 127.9p per litre for petrol, more than 5p a litre less than across the UK as a whole, and 134.5p per litre for diesel, which is 7p a litre cheaper than the UK average. Membership-only Costco charge even less, with a litre of petrol averaging 125.9p and diesel 133.7p.

RAC head of policy Simon Williams said: “While it’s good news that two months of rising fuel prices have come to an end, it’s disappointing that high retailer margins are preventing drivers from benefitting from lower prices.

“The Competition and Markets Authority’s latest report confirms that retailer margins are far higher than they were historically, and that competition remains weak. Our analysis of pricing data confirms the latter, with just a handful of forecourts appearing to compete heavily on price, with the exception of those in Northern Ireland where drivers enjoy far cheaper fill-ups than in any other corner of the UK. This is no doubt a source of ongoing frustration for many of the nation’s motorists.

“We hope that greater transparency of fuel prices from the end of this year means that a spotlight is shone on both those forecourts that charge the fairest prices and indeed, those that sell petrol and diesel for far higher amounts.

“In the meantime, there are still some good deals to be had if drivers know where to look. The free myRAC mobile app – which is available to our members and non-members alike – pinpoints good-value forecourts and can help ensure drivers pay as little as possible every time they need to fill up.”