In the UK for every 1 litre of unleaded consumed 2 litres of diesel are consumed. Diesel is used globally for heating, shipping and road transport.
The UK produces more unleaded than it uses and is a net exporter of unleaded. However, we are ‘short’ of diesel, meaning the UK’s requirements are greater than its production. Diesel is imported to make up the shortfall. This structural imbalance can leave the UK more exposed to diesel supply disruptions than unleaded. In 2025 the UK was a net importer of 4 million tonnes of diesel and a net exporter of 3.5 million tonnes of unleaded.
In addition to this, and more importantly is the type of oil that comes via the Strait of Hormuz.
Not all crude oil is the same, and there are two main attributes that can help categorise oil; how ‘sweet or sour’ it is and how ‘light or heavy’ it is.
The sulphur content of the crude defines if the crude is sweet (low sulphur) or sour (high sulphur). Sulphur is an impurity that may need to be removed, and so sweet crudes tend to be more valuable than sour crudes.
The ‘American Petroleum Institute Gravity” or “API Gravity” is a measure of how heavy the crude is. Lighter crudes, which have a higher API Gravity value, will yield a higher percentage of lighter more valuable products such as gasoline.
In the US the West Texas Intermediate (WTI) is the main crude grade, and it would be categorized as a light sweet crude, perfect for refining high quality gasoline. In the UK our main crude is Brent, named after the Brent oil fields in the North Sea, it is also a light sweet crude, although not as light or as sweet as WTI.
WTI has a typical sulphur content of 0.24 to 0.34% and an API gravity 39-40. With a typical refining yield of 24% diesel and 46% gasoline.
Arab Light, one of the major crude benchmarks affected by the effective closure of the Strait of Hormuz, typically has a 1.7% sulphur and 31.7 API gravity and would be classed as a medium sour crude. A typical yield would by 40% diesel and 25% gasoline. Middle East medium sour crude raced to all-time highs over Brent last week.
The properties of the oil heading east to China and India are like that of Russian Urals, which had been sanctioned by the US, however these sanctions have been temporarily lifted due to the supply disruptions. The price of Urals deliveries to India has surged to a premium over Brent for the first time since September. Urals was priced at $22 a barrel over Brent on Monday, the highest level since at least December 2022.
Limiting supply of crudes that yield higher volumes of diesel has been a major factor in driving diesel prices higher. This in turn has pushed the price of heavier crude oils higher. Traditionally Brent and WTI have traded at a premium to heavier crude benchmarks however that has narrowed and even reversed since the US and Israeli strikes on Iran.
Absolute profiteering by the forecourts. Oil companies have more than ample quantities of fuels at there depots…The war is only 1.4 wks old and there is no way that there gave been further supplies .
There is no regard for the customer and customers should boycott the forecourts..
Why is it that prices differ and have increased by so much in such a short time.
Hi John, thanks for your comments. It is very difficult to get site of a fuel stations individual cost prices – what we do know, is how some of them buy fuel. Some stations are priced by their supplier on the average day of wholesale fuel (plus suppliers margin) from the day before. If the wholesale price of fuel goes up 10ppl or more overnight (which has been happening) then your cost price has gone up over 10ppl or more. You can read a bit more about how fuel is bought and priced here: https://www.petrolprices.com/news/how-do-petrol-stations-purchase-fuel/
The real gripe we think, is that over 50% of the pence per litre is a tax, and if the UK Gov wanted to support motorists they’d review Fuel Duty and the VAT rate.
Why are we exporting unleaded when it should be diverted to UK forecourt to help with the cost crisis? Profit over national security overtime and these oil companies get away with massive profits while Joe Public suffers. More fuel kept here raises more revenue for the government coffers too AND looks after the people who the government is supposed to serve. Even when this war ends and things go back to normal, I doubt prices will revert to pre-war levels and we’ll be stuck with artificially over inflated prices.
Good questions. The complicated part is the make up of ownership, the vast majority of fuel stations in the UK aren’t owned by the Oil Co directly but they set the price in which they supply the site. Some stations are priced by their supplier on the average day of wholesale fuel (plus suppliers margin) from the day before. If the wholesale price of fuel goes up 10ppl or more overnight (which has been happening) then your cost price has gone up over 10ppl or more. You can read a bit more about how fuel is bought and priced here: https://www.petrolprices.com/news/how-do-petrol-stations-purchase-fuel/
The real gripe we think, is that over 50% of the pence per litre is a tax, and if the UK Gov wanted to support motorists they’d review Fuel Duty and the VAT rate.
Total Production Cycle: From the moment crude oil is discharged, it is generally part of a continuous process, but it may sit in “charging tanks” temporarily. The overall process to get fuel from a refinery, including storage and testing, usually takes around four weeks to reach the final distribution point, though this can be accelerated to two weeks under high demand.
Don’t forget that in this country, a substantial part of the pump price is tax. So the government benefits from the price rising.
Absolutely! We think that is the real problem over 50% of the pence per lite is a tax, and if the UK Gov wanted to support motorists they’d review Fuel Duty and the VAT rate.
My family and I live on the most easterly coastal arez in mainland UK, we often see oil tankers – that are usually fully laden – sat out at sea on the horizenfor days (even sometimes weeks!!) waiting for predicted oil prices to rise. It’s gone on for years, and I’m sure our coast is not the only place this happens?! When prices begin to fall, there are very rarely the same queues of tankers. The owners and oil companies are yet to pass on the savings from those times of lower prices to customers! As for the fuel duty? Don’t even get me started! It’s a rare day indeed that the public can put thier hands in thier pockets without removing the ruling goverment’s hands first – regardless of which party is in power!!
Diesel was 157.9p on Thursday evening but 166.9p today at the same Tesco, an increase of 9p/litre in just 3 days. The prices are still relatively cheap for the area, but the amount of increase is staggering, especially as just a few weeks ago I bought diesel at 137.9p at the same garage.
The government must be making £bn out of us in extra VAT!
How can one station charge 20 pence more for a litre than another and both are getting there fuel from the same fuel company
Profiting from the whole war situation is all there is to say. The govt don’t care about the public and the prices will stay inflated for a whole lot longer. An increase of over 40p per litre in 3 weeks for diesel is simply put……. ridiculous!!!