UK diesel hits all-time high of 199.18p as RAC cites ‘uncharted territory’
Russia has imposed a diesel export ban following attacks on its refineries by Ukraine, compounding international supply pressure already intensified by the seven-month US-Iran conflict. Together, these forces have helped push UK diesel to an all-time average of 199.18p per litre on 28 September 2026, the motoring organisation RAC reported.
The RAC said diesel prices had entered “uncharted territory” and served as a reminder of “just how exposed the UK is to events occurring far away.” The 199.18p average recorded on Monday surpasses the previous record of 199.09p set in June 2022.
International diesel supply had already been heavily constrained by the Iran war, which has restricted the flow of both crude oil and refined diesel onto global markets. The price of Brent crude, a benchmark for global oil used to make petrol, diesel and other fuels, rose over the weekend and was hovering at around $108 a barrel. Before the US invaded Iran, Brent had been trading at around $73.
The RAC’s price series is based on average diesel prices at supermarkets, motorway service stations and independent retailers.
Diesel has climbed 59p a litre, just under 40%, since the US-Iran conflict erupted at the end of February. That translates into a £31 rise in the cost of filling an average family car with diesel, taking that fill-up to £110. Petrol prices have continued rising alongside, with a litre now costing 174.13p — 41p more than at the start of the conflict, but still well below the 2022 peak.
Simon Williams, the RAC’s head of policy, said the diesel record “spells pain not only at the pumps for drivers, but for everyone who buys goods or services that rely on diesel lorries and vans.” He added: “Undoubtedly these increased costs will be passed on to consumers.” Williams said prices at the pumps will not come down until there is a “sustained lower oil price — over several weeks, not days.”
Russia, which is also a major diesel producer, has implemented the export ban following attacks on its refineries by Ukraine, further limiting supply. Diesel is harder to refine than gasoline and, because it is used by the haulage industry and in agriculture, demand is difficult to reduce.
The UK is structurally reliant on diesel imports. The country’s four refineries produce more than enough petrol to meet domestic demand but do not produce enough diesel for the country’s needs.
There were 15.1 million diesel vehicles on UK roads at the end of June 2026, according to the Department for Transport, down from 15.7 million a year earlier. The number of diesel cars fell from 10.4 million to 9.8 million over the same period.