UK drivers are continuing to pay more at the pump, with retail fuel margins sitting well above historic norms, according to the Competition and Markets Authority’s (CMA) latest monitoring report.
The watchdog’s update, published on Friday, shows average petrol prices rose to 133.9 pence per litre (ppl) and diesel to 141.9ppl between May and August 2025 – increases of 1.9ppl and 3.5ppl respectively. While global oil market movements explain some of the rise, the CMA said persistently high margins indicate retailers are retaining more profit than in the past.
“What’s deeply concerning is that fuel margins – a key indicator of retailer profit – remain far above historic levels,” Dan Turnbull, Senior Director of Markets at the CMA, said.
“The Fuel Finder scheme we recommended to government will help combat this trend, pushing retailers to be more competitive as drivers are empowered with real-time pricing data.”
Margins more than double 2017 levels
The report found that supermarket fuel margins averaged 8.4 per cent in the first half of 2025 – more than double the 4 per cent seen in 2017. Non-supermarket retailers also saw margins rise to an average of 9.8 per cent over the same period, compared with 6.4 per cent in 2017.
From April to June this year, supermarket margins ranged from 8 to 9.1 per cent, while other retailers saw returns of 9.9 to 10.6 per cent.
This monitoring update does not consider developments in operating costs. The CMA will undertake a review of fuel retailer operating costs in its first annual road fuel monitoring report, which is set to be issued at the end of the year. This will assess whether changes in costs are impacting fuel margins for large retailers.
Retail spreads remain inflated
The report also highlighted retail spreads – the difference between pump prices and wholesale benchmarks. From June to August 2025, petrol spreads averaged 13.3ppl and diesel 13.3ppl, despite small decreases compared to the spring. These remain well above pre-pandemic averages of 6.5ppl for petrol and 8.6ppl for diesel.
While spreads fluctuate with wholesale markets, the CMA said they should return to normal ranges over time “if the market is working well.”
Fuel Finder scheme on track for launch
The government is working towards launching the CMA-recommended Fuel Finder scheme by the end of 2025. The digital service will give motorists access to real-time pump prices through satnavs, comparison sites, and in-car systems, making it easier to shop around.
Retailers across the board – including BP, Shell, Esso, Tesco, Sainsbury’s, Asda, Motor Fuel Group, and Rontec – have been required to provide data to the CMA under its statutory monitoring powers.