As of Friday the 25th September 2026, the average price of diesel for a litre placed at 198.32 pence, with petrol priced at 173.6p per litre.
Since the start of September, Diesel prices have increased by more than 14ppl in the UK.
The RAC's head of policy, Simon Williams said,
"The average price of diesel is teetering on the brink of a new all-time high at 198.32p, taking the cost of a 55-litre fill-up for a family car to £109.
The UK now has the most expensive diesel in Europe by 12p a litre ahead of Finland and the Netherlands.
The record of 199.09p will almost certainly be surpassed over the weekend as retailers continue to pass on the increases they’re seeing when they buy new supply.
Petrol is now averaging 173.6p – its highest price in more than four years. Petrol has risen nearly 12p in September and more than 40p since the Iran War began.”
Since the Iran war beginning, in February 2026, diesel prices have risen 55ppl.
Williams said: “Sadly for drivers, there appears to be no end in sight to high prices at the pumps as the cost of a barrel of oil hit $106 having been around that $100 mark for the last two weeks.
“A significant drop in the price of oil is badly needed but this seems unlikely without the US and Iran striking a deal.”
Fuel prices continue to rise as the US considers introducing a diesel export ban to help reduce costs for American motorists.
The proposed ban could have implications for the UK, which sources around 31% of its diesel imports from the US. Any restrictions on exports could further increase fuel prices for British drivers.
