Why has UK diesel risen twice as fast as petrol since February 2026?

Since the Middle East crisis that began on 28 February 2026, UK pump prices have risen across the board — but not evenly. Petrol is up roughly 25 pence a litre. Diesel is up 48. One fuel has risen nearly twice as fast as the other.

That gap is not arbitrary, it's not a pricing error, and it's not going away quickly. It's the product of structural differences in how petrol and diesel move through the global market — differences that most drivers never need to think about until an oil shock puts them under a microscope.

Here's exactly what's happening, why, and what it means for what you're paying at the pump.

The numbers, side by side

Based on UK fuel price trends and wider industry reporting:

For context, the historical petrol–diesel gap in the UK has typically hovered between 5p and 10p per litre. A 23p gap is genuinely unusual — last seen during the worst of the 2022 post-Russia-invasion fuel spike.

What triggered it: the 28 February Middle East shock

The immediate cause is well documented. On 28 February 2026, escalating military action in the Middle East disrupted shipping through the Strait of Hormuz, the narrow waterway that carries roughly 20% of global oil supply and a disproportionately large share of refined diesel and jet fuel exported from Middle Eastern refineries.

Brent Crude — the UK's reference benchmark — rose above $85 a barrel within days, its highest level since mid-2024. Because the UK buys crude in US dollars and the pound weakened simultaneously, the import cost shock was sharper here than in several comparable European economies.

That's the petrol story. But for diesel, the shock was layered on top of several pre-existing pressures that don't apply to petrol in the same way.

Why diesel rises faster than petrol in almost every oil shock

There are four structural reasons, and all four have been pulling in the same direction since late February.

1. Middle East refineries produce proportionally more diesel

Middle Eastern crude and Middle Eastern refining capacity skew towards middle distillates — diesel, jet fuel, heating oil — rather than petrol. When supply from that region is disrupted, the global pool of diesel shrinks faster than the global pool of petrol. The UK, which imports a significant share of its diesel, feels this more acutely than countries that are net diesel exporters.

2. Europe has a structural diesel deficit

Unlike the US, which runs a petrol-heavy refining slate, most European countries — the UK included — consume more diesel than their refineries produce. The shortfall is covered by imports, much of it from the Middle East, Russia (now largely replaced by alternatives post-sanctions), and the US Gulf Coast. Any squeeze on global diesel tightens the European market first.

3. Diesel demand is far less flexible

When petrol spikes, some drivers defer journeys, work from home more, or switch to public transport. Diesel demand barely flinches. Almost every HGV, delivery van, bus, and agricultural vehicle in the UK runs on diesel, and none of them have a realistic alternative on a month-to-month basis. When demand is inelastic, prices adjust upwards faster and correct downwards more slowly.

4. The biodiesel blend economics have broken

Standard UK diesel (B7) contains up to 7% biodiesel — usually fatty acid methyl ester (FAME) — blended in to meet the UK's Renewable Transport Fuel Obligation. Normally, FAME acts as a price stabiliser: when mineral diesel spikes, the FAME component softens the blow at the pump.

In this crisis, that hasn't happened. FAME prices have stayed roughly flat while mineral diesel has surged, so the "renewable discount" embedded in a litre of B7 has collapsed from around 8p earlier in the year to under 1p now. That alone has added several pence to pump prices that petrol-only blends weren't exposed to.

The wholesale vs. retail gap: is someone profiteering?

Here's where it gets uncomfortable for retailers. Industry analysis by PetrolPrices.com has tracked wholesale diesel up by around 41p since late February — a 74% rise on pre-crisis levels. Retail diesel is up 48p. On the surface, retailers look as if they've held the line reasonably well, passing on roughly the wholesale rise and no more.

But the detail matters. In the CMA's own language from their road fuel market study, UK fuel retail has historically shown a "rocket and feather" pricing pattern — prices rise quickly when wholesale goes up, and fall slowly when wholesale comes down. We're currently in the rocket phase. The real test comes over the next few weeks: if Brent stabilises or falls and pump prices don't follow within a reasonable lag, that's when the CMA's Fuel Finder transparency scheme — and sites like PetrolFinder that use it — start to reveal which retailers are moving with the market and which aren't.

You can see which stations are currently pricing above the local and national average in real time.

What it actually costs UK drivers

The per-tank reality is stark. A typical 55-litre fill:

• Petrol (up 25p/L): £13.75 more per tank than before 28 February
• Diesel (up 48p/L): £26.40 more per tank than before 28 February

For an HGV running multiple tankfuls a week, the diesel increase alone translates to thousands of pounds a month in extra operating costs — costs that, unlike for domestic motorists, are almost always passed through into the price of goods on shelves and in deliveries. Expect the divergence to show up in grocery inflation figures in the next couple of quarters, not just at the pump.

When will it correct?

Three things need to happen for the petrol–diesel gap to normalise:

1. Brent Crude needs to stabilise or fall. Analyst consensus depends heavily on whether Middle East tensions de-escalate or entrench.
2. Global diesel supply needs to recover to pre-crisis flows — which takes longer than crude because refined product inventories need to rebuild.
3. Retailer pass-through needs to happen on the way down — historically the slowest part of the cycle, and the reason the CMA set up the Fuel Finder scheme in the first place.

Even in an optimistic scenario, the gap is likely to remain wider than normal until at least late summer. Meanwhile, the temporary 5p fuel duty cut expires at the end of August 2026, at which point pump prices face a further structural upward pressure on top of whatever the wholesale market is doing.

TL;DR

• UK petrol is up ~25p/L since the 28 February Middle East crisis. Diesel is up ~48p/L — nearly twice as much.
• Four structural reasons: Middle East refineries skew towards diesel, Europe runs a structural diesel deficit, diesel demand is inelastic, and the biodiesel blend buffer has collapsed.
• Retail pricing is currently tracking wholesale reasonably closely on the way up. The real test comes when wholesale falls.
• A 55-litre diesel fill now costs roughly £26 more than it did in February. A petrol fill costs roughly £14 more.
• Fuel duty rises return from September 2026, adding further upward pressure.

For live pump prices at every UK forecourt — updated every five minutes from the official government Fuel Finder feed — use our live fuel price map.

Sources and further reading

• UK Fuel Market Update April 2026: Diesel Leading the Price Surge — PetrolPrices.com: petrolprices.com/news/uk-fuel-market-update-april-2026
• Fuel Watch: latest UK petrol and diesel prices — RAC: rac.co.uk/drive/advice/fuel-watch
• Road fuel market study — Competition and Markets Authority: gov.uk/cma-cases/road-fuel-market-study
• Fuel duty rates 2026 to 2027 — HM Treasury and HMRC: gov.uk/government/publications/fuel-duty-rates-for-2026-to-2027
• Quarterly Energy Prices — Department for Energy Security and Net Zero: gov.uk/government/collections/quarterly-energy-prices
• Renewable Transport Fuel Obligation — Department for Transport: gov.uk/guidance/renewable-transport-fuel-obligation
• Access fuel price data (Fuel Finder scheme) — Department for Energy Security and Net Zero: gov.uk/guidance/access-fuel-price-data

All figures in this article were verified against the sources above on 21 April 2026. Pump prices quoted are UK averages drawn from live Fuel Finder data; regional and station-level prices will vary.

About the author — Wayne founded PetrolFinder UK in 2025. The site tracks live pump prices at more than 7,500 UK forecourts using the UK government's official Fuel Finder dataset, updated every five minutes. PetrolFinder UK is licensed under the Open Government Licence v3.0 for its use of CMA/DESNZ data. Read more about us.

About PetrolFinder UK — We track live petrol and diesel prices at every UK forecourt using the government's Fuel Finder dataset, updated every 5 minutes. Find the cheapest fuel near you → · Price trends · Price watch · Supermarket prices