UK diesel drivers are finally seeing some relief at the pumps.

The average price of diesel is falling for the first time in months, narrowing the record gap between diesel and petrol.

Prices have reached record levels, with diesel rises outpacing those of petrol, following the US/Israeli attack on Iran and the subsequent disruption to shipping through the Strait of Hormuz.

Put that in your tank.

New figures from RAC Fuel Watch show that the average price of diesel fell by 4.5p per litre during May to 183.9p, while petrol increased by 2.4p per litre to 159.4p.

The result is that diesel drivers are now paying around £2.50 less to fill a typical 55-litre family car than they were a month ago, while petrol motorists face an extra £1.32 per tank.

The decline marks a significant shift from the dramatic fuel price rises seen earlier this year when global oil markets were shaken by military action involving Iran and restrictions on traffic through the Strait of Hormuz, a key route for around a fifth of the world’s traded oil.

At the height of the crisis in April, average UK diesel prices exceeded 190p per litre, having risen by almost 48p since the outbreak of hostilities, while petrol climbed by nearly 25p.

Small improvements

Despite the recent fall, diesel remains substantially more expensive than it was before the Middle East crisis.

Before the conflict, RAC figures showed average diesel prices at around 142p per litre, compared with today’s 183.9p.

Petrol has risen from approximately 133p per litre before the conflict to 159.4p today.

The RAC said falling wholesale diesel costs largely drove the recent reduction, while wholesale petrol prices moved in the opposite direction during May.

“The price differences were caused by the wholesale cost of petrol rising mid-month while the diesel equivalent reduced,” the RAC said, noting that the wholesale gap between the two fuels narrowed considerably during the month.

Historically, diesel has often been slightly more expensive than petrol in the UK, but the gap widened dramatically during the spring as supply concerns hit diesel harder.

Industry analysts point to the UK’s reliance on imported diesel, strong demand from freight, logistics, and agriculture, and competition from heating oil markets as key reasons diesel prices surged more sharply than petrol prices.

Volatile products

For motorists, the latest figures suggest the worst of the diesel price spike may be over, although experts warn that pump prices remain vulnerable to further geopolitical instability.

The International Monetary Fund this week noted that oil prices remain above the levels assumed in its spring economic forecasts.

It warned that future movements will depend heavily on developments in the Middle East and whether normal shipping patterns through the Strait of Hormuz can be maintained.

Compared with many European countries, UK fuel prices remain towards the upper end of the scale, although differences in fuel taxation and duty regimes make direct comparisons difficult.

Across Europe, fuel prices rose sharply following the conflict in Iran, with average petrol prices in the EU increasing by around 12% in the weeks after the outbreak of hostilities.

The UK government suspended the planned 5p per litre rise in fuel duty, freezing the rate until the end of 2026.

This measure maintains petrol and diesel duty at its lowest rate in over 16 years, saving the average driver about £120.

Finding cheaper fuel

Motoring organisations continue to urge drivers to shop around for fuel, noting that significant regional and retailer differences remain.

RAC head of policy Simon Williams said motorists should continue to use fuel price comparison tools, including the government’s Fuel Finder, to find the best deals, particularly as independent retailers are often quicker to pass on wholesale savings than larger operators.

Fuel cards can also save motorists significant costs, especially those who use their vehicles for work.

With global oil markets still sensitive to geopolitical developments, fuel costs remain significantly above pre-conflict levels, and further volatility cannot be ruled out.