RAC: Price of a litre of diesel shoots up by another 8p in September while petrol increases unjustifiably by another 4.5p

• Diesel is now nearly 17p more expensive that at the start of August. September was the third consecutive monthly increase
• Petrol up 11p since beginning of August but is at least 7p overpriced. Last month was the fourth consecutive monthly increase

The average price of diesel rocketed by more than 8p a litre in September and petrol by 4.5p on the back of global oil production cuts which have driven the cost of a barrel close to $100, data from RAC Fuel Watch* shows. 

Diesel shot up from 154.78p at the start of the month to 163.11p by the close (8.33p) making for its fifth biggest monthly rise since 2000. Unleaded went up from 152.49p to 157.01p (4.52p), its 13th biggest monthly jump in price in the last 23 years. This is on top of rises drivers suffered in August, when petrol went up by nearly 7p and diesel by another 8p.

The increases mean it now costs nearly £90 to fill up a 55-litre family diesel car – around £4 more in a month, and the highest cost since April – and more than £86 for a similar petrol car, an increase of over £2 in September and the highest cost since December 2022

The RAC says the price rises are being driven by oil producer group OPEC+ restricting global supply in conjunction with the weaker value of sterling which makes wholesale fuel, which is traded in dollars, more expensive to buy in the UK. Throughout September the cost of a barrel went from just under $89 to around $96 which added 8p a litre to the wholesale price of diesel. The last time oil was traded for over $100 a barrel was at the end of August 2022.

RAC fuel spokesman Simon Williams said: “Drivers are sadly really starting to suffer again at the pumps with September seeing another 8p a litre added to the average price of diesel which comes hot on the tail of a similar increase in August. Petrol has also gone up 11p since the beginning of August so there’s little respite whichever fuel drivers use.

“Our analysis of RAC Fuel Watch wholesale and retail data shows that petrol is currently overpriced by around 7p a litre, although the price of diesel is likely to go up further still in the coming weeks. 

“It’s worrying that retailer margin across the UK is higher for petrol than it should be considering the big four supermarkets were told off by the Competition and Markets Authority for overcharging drivers by £900m in 2022. While many have voluntarily started to publish their prices ahead of being mandated to in law, we still have a situation where wholesale price changes aren’t being fairly reflected on the forecourt. 

“In the last two weeks the wholesale cost of diesel has become 10p a litre more expensive than petrol, yet the gap at the pumps is only 5p. If retailers as a whole were playing fair with drivers petrol would be at least 7p cheaper than it is now, down to around 150p from its current average of 157p.

“The second recommendation from the CMA report was to set up a price monitoring body which this situation demonstrates the need for as some retailers are clearly inflating the price of petrol. The setting up of this body cannot come soon enough, as long as it has some form of teeth to keep retailers in line.” 

Those looking to save as much as possible at the pumps should download the free myRAC app from the App Store or Google Play and take advantage of its Fuel Finder feature as it can shave off up to 6p a litre – or as much as £3.30 for every full 55-litre tank**. 

Users can make up to five searches a day over a two, five or 10-mile radius from their chosen locations, with each giving the five cheapest forecourts. Unlike other apps, the average prices for both petrol and diesel are displayed making it easy to compare against local forecourts. 

More information about petrol and diesel prices can be found on RAC Fuel Watch including the average price of petrol and diesel at the big four supermarkets and at motorway services. There are also graphs showing average prices since 2000 as well as a daily financial breakdown of the cost of a litre of petrol and diesel.

Regional pump prices

Ends

Notes to Editors

* UK national average pump prices quoted are based on Experian Catalist data from 1-30 September 2023. Wholesale prices, oil price and the value of sterling are based on data from 1-29 September 2023

** The myRAC Fuel Finder uses data from Experian Catalist to help drivers find the cheapest fuel near them, or any location they want to search. Experian Catalist collects fuel prices for all main fuel types from just about every forecourt across the UK and updates prices the following day. Prices are updated at around 8am every day of the year, including weekends and bank holidays. The 6p saving is based on difference between average and lowest diesel price in 20 areas selected at random; 5p average saving for petrol. As of 07/06/23.