Diesel Records Biggest Monthly Drop as Pump Prices Fall Sharply
UK diesel prices recorded their largest single-month fall on record during June 2026, dropping from 183.75p per litre to 167.14p per litre. Petrol also fell sharply, down 7.97p from 159.37p to 151.40p per litre over the same period. The reductions followed a steep slide in the price of Brent crude oil after the US and Iran agreed a framework deal to end the conflict in the Middle East.
For drivers, the fall is a welcome break after months of pressure at the pumps. A full tank of diesel now costs roughly £9 less than it did at the start of June, while a typical 55-litre petrol tank costs around £4.40 less. The question now is whether prices can keep falling or whether the relief is temporary.
What the RAC Fuel Watch data shows
RAC Fuel Watch, which analyses Government Fuel Finder data, published a news release on 2 July 2026 setting out the scale of the June falls. According to the RAC, the average price of diesel started June at 183.75p per litre and ended the month at 167.14p per litre, a fall of 16.6p. The RAC said this was the largest monthly drop since it began compiling the data in 2000, exceeding the previous record of 11.92p set in May 2023 by almost 5p.
Petrol also fell significantly. The average price of unleaded petrol dropped from 159.37p per litre to 151.40p per litre in June, a fall of 7.97p. The RAC described this as the seventh-greatest monthly fall in the last 26 and a half years.
The price reductions were driven by a fall in the wholesale oil price. A barrel of Brent crude, the global benchmark for oil, slid from $94.98 at the start of June to $72.92 by 30 June, according to the RAC. The drop came after the US and Iran agreed a framework deal to end the conflict that began on 28 February 2026.
Supermarket forecourts cut prices even more aggressively for diesel. The RAC reported that the big four supermarkets reduced their average diesel price by 19.05p per litre, from 182.37p to 163.28p. Supermarket unleaded fell by 7.15p per litre, slightly less than the UK-wide average.
Motorway service areas also saw reductions, though smaller for diesel. Unleaded on the motorway network fell by 8.11p, from 179.78p to 171.67p per litre. Diesel on motorways fell by 13.83p, from 201.07p to 187.24p per litre.
Context: how prices compare with recent months and the pre-war level
Although June's falls are substantial, prices remain well above where they were before the Middle East conflict began. According to the BBC, average petrol prices were around 132p per litre and diesel around 142p per litre at the start of the war on 28 February 2026.
During the conflict, prices reached much higher levels. The RAC told the BBC that petrol peaked at 159.53p per litre on 28 May, while diesel hit 191.54p per litre on 15 April. Diesel's June fall therefore followed a rise of roughly 49p per litre in under two months.
The latest official weekly road fuel price statistics from GOV.UK, last updated on 30 June 2026, provide a separate benchmark. While the release does not publish daily averages, it confirms the weekly series is current to the end of June and tracks unleaded petrol and ultra-low sulphur diesel retail pump prices across the UK.
At the time of writing, PetrolPricesNearYou's own live fuel price feed, based on the Government Fuel Finder, shows the UK average price for E10 petrol at 150.6p per litre as of 6 July 2026. This is consistent with the RAC's end-of-June figure and suggests prices have held broadly steady into the first week of July.
What this means for drivers
For most drivers, the immediate impact is straightforward: filling up is cheaper than it was a month ago. The RAC calculated that a 55-litre tank of petrol now costs £83.27 on average, down from £87.65 at the start of June. A full tank of diesel costs £91.93 on average, down from £101.06.
Whether prices fall further depends mainly on the oil price and the pound-dollar exchange rate. The RAC said in its 2 July release that petrol should dip below 150p per litre and diesel should fall below 160p per litre, provided oil stays in the low-$70s range or falls further. However, the motoring group also warned that prices are still some way off pre-conflict levels.
There is also a domestic factor that could push prices back up later in the year. The 5p-per-litre fuel duty cut introduced during the cost-of-living crisis is currently scheduled to be unwound in stages from September 2026. When that happens, duty will rise in three steps, adding roughly 6p per litre to pump prices by March 2027. For now, the cut remains in place, but drivers should expect upward pressure in the autumn.
Northern Ireland continues to have the cheapest average prices in the UK. The RAC reported average petrol at 147.5p per litre and diesel at 162.6p per litre in Northern Ireland at the end of June. Within England, the RAC highlighted GW Holmes of Etherley Moor Garage in Bishop Auckland at 139.7p for petrol and Linthouse Lane Service Station in Wolverhampton at 152.9p for diesel, matched by two Sainsbury's sites in the same city.
How to save on fuel
Prices vary widely between forecourts, so shopping around remains the easiest way to cut costs. Three practical tips:
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Compare prices before you leave. The Government's Fuel Finder scheme requires forecourts to report price changes within 30 minutes. Use a live price tool such as PetrolPricesNearYou to find the cheapest petrol near you rather than driving between stations.
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Check supermarket and independent forecourts. Supermarkets often have the lowest headline prices, but smaller independent sites can undercut them. The RAC noted that smaller forecourts in England are currently selling some of the cheapest fuel in the country.
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Fill up before motorway services. Motorway forecourts are consistently the most expensive place to buy fuel. If possible, refuel near your start point or final destination rather than on the motorway network, where unleaded averaged 171.67p and diesel 187.24p per litre at the end of June.
Sources
- RAC Fuel Watch: Diesel drops by record 17p a litre in June, while petrol falls 8p — 2 July 2026
- BBC News: Diesel sees biggest monthly fall in 26 years. What's happening to fuel prices? — updated 2 July 2026
- GOV.UK: Weekly road fuel prices — last updated 30 June 2026