LONDON, March 17, 2026, 19:49 GMT
UK petrol prices rose again on Tuesday, opening a near-49 pence-a-litre gap between one of the priciest motorway stops on the M1 and the cheapest station listed in London, as conflict-linked supply fears kept crude above $100 a barrel. RAC data showed average unleaded at 142.29p a litre and diesel at 162.06p, while checks by the Guardian and Secret London pointed to a spread from 172.9p on the M1 to 123.9p in Camden. 1
The widening gap matters now because drivers are dealing with two shocks at once: national prices are still rising, and local differences have become big enough to make route choices matter. It also lands as ministers push the new Fuel Finder price-reporting scheme and warn retailers against using the Middle East crisis as cover for unjustified increases, while Finance Minister Rachel Reeves said on Tuesday the Iran conflict was likely to put upward pressure on UK inflation in the months ahead. 2
Brent crude, the international oil benchmark, was up 1.3% at $101.53 a barrel by 1515 GMT, Reuters reported. The move followed renewed Iranian attacks on the UAE, partial disruption to loadings at Fujairah and continuing problems in the Strait of Hormuz, the narrow route that carries about a fifth of the world’s oil and liquefied natural gas trade; IG analyst Tony Sycamore said “the risks remain stark.” 3
At the pump, the speed of the pass-through is what motorists are noticing. RAC head of policy Simon Williams said petrol has risen by about 10p a litre since the Iran conflict began and diesel by nearly 20p, calling it “really starting to hurt drivers,” with diesel motorists now paying about £11 more than at the end of February to fill a typical tank. 1
The squeeze looks harsher on motorways. Woodall services on the M1 near Sheffield was charging 172.9p for petrol and 185.9p for diesel in the Guardian’s latest check, far above the national averages, and the site operator said its pricing reflected the wider motorway market and rising fuel costs. 4
Cheaper pockets remain, especially in London. Petrol Map analysis cited by Secret London put Morrisons Camden at 123.9p a litre, an Asda site on Old Kent Road at 128.7p, and Tesco sites in Southwark and Canada Water at 128.9p, with south-east London described as the cheapest area in the capital. 5
That matters more because Fuel Finder only started mandatory reporting on Feb. 2. Under the scheme, all public petrol and diesel sellers must register and update prices within 30 minutes of a change, and the government says greater transparency could save car-owning households about £40 a year; ministers said on Sunday that Asda’s sign-up would take the scheme’s reach to almost 100% of pumps nationwide. 6
The Competition and Markets Authority has already brought forward demands for revenue, cost and sales data from retailers responsible for thousands of filling stations, and said it would check for “rocket and feather” pricing, industry shorthand for prices that shoot up quickly when wholesale costs rise but drift down slowly when those costs ease. Juliette Enser, the watchdog’s executive director for markets, said increases should reflect “genuine cost pressures.” 7
Ministers are worried about more than commuting bills. Reeves said on Tuesday the conflict was likely to push inflation higher in the coming months, and the government announced a £53 million package on Monday to help vulnerable households absorb rising heating-oil costs, a sign that the energy shock is already spilling beyond the forecourt. 8
But the next move is still not settled. Some tankers have begun to pass through Hormuz again and the International Energy Agency has floated further reserve releases, which could cool prices if flows improve; even so, Williams said petrol should stay below 148p only if oil holds around $100, while diesel appears on course for 170p if the disruption drags on. 3
