The average price of petrol rose by 4p a litre in February while diesel shot up by nearly 5p in the biggest monthly increases in five months, data from RAC Fuel Watch* shows.

Unleaded went up from 140.75p at the start of the month to 144.76p by the close, adding more than £2 to the price of a full tank (£77.41 to £79.62). Diesel jumped from 148.53p to 153.22p (4.7p) increasing the cost of filling up an average 55-litre family car by £2.60 to £84.27.

The hikes have been driven by the price of oil breaking through the $80 a barrel mark on 8 February and staying there for the rest of the month. This, combined with the pound only being worth $1.26 meant retailers had to pay more for fuel on the wholesale market as – similar to oil – fuel is traded in dollars.

RAC Fuel Watch data also shows that drivers in Northern Ireland are still getting a far better deal at the pumps, with unleaded being sold 5.6p cheaper and diesel 4.6p cheaper (139.19p for petrol and 148.62p for diesel).

RAC analysis of prices from the Government’s voluntary open data scheme on 29 February shows petrol is just under 2p (1.8p) cheaper when bought at one of the country’s big four supermarkets (143p v 144.76p) and diesel is only a penny cheaper (152.1p v 153.22p). It also highlights that there is an 18p-per-litre difference between the supermarket forecourts selling the lowest and highest priced unleaded, both of which are Asda sites. The lowest price was 136.7p at its sites in Middleton, Leeds, and Ballyclare, north of Belfast in Northern Ireland, and the most expensive was 154.9p at Parkgate Road in Chester.

For diesel, the gap between the cheapest and most expensive supermarket forecourts is greater at 21p. Tesco offered drivers the lowest priced at 142.9p at Banbridge in Northern Ireland and Asda had the dearest at 163.9p, again at Parkgate Road in Chester.

RAC fuel spokesman Simon Williams said: “Our data shows that in February, drivers endured the highest monthly average fuel price increases since September 2023. Diesel’s 4.7p rise was the 14^thlargest and the 4p that went on to petrol was the 17^th biggest increase since the start of the century.

“What’s especially galling is the continuing difference in price between Northern Ireland and the rest of the UK. On average fuel is 5p cheaper there, with big retailers appearing happy to operate on thinner margins per litre.

“Looking at average margins across the whole of the UK, retailers are currently taking around 10p a litre on average across both petrol and diesel. The supermarkets in particular have now noticeably upped their margins to 8p a litre compared to 6p in 2019. Luckily for drivers, this is lower than the last two years when it was around 9.5p.

“When analysing the supermarkets’ prices via the Competition and Markets Authority open data scheme, it is also very clear there are some big differences between the cheapest and most expensive prices charged for both petrol and diesel. Frighteningly, at the end of February there was an 18p difference between the country’s cheapest supermarket unleaded and the dearest, and for diesel it was 21p. To put this into a context, it means the cost of filling a family-sized car can be up to £10 more expensive in one part of the country than another. It’s important to remember this is the very same product being charged at vastly different prices based just on location.

“We hope that the eventual introduction of the monitoring body recommended by the Competition and Markets Authority will help to bring an end to this postcode lottery that treats drivers so unfairly.”

Motorists looking to save money on their fill-ups should start using the fuel finder feature in the free myRAC app. The app can be downloaded for free from the App Store or Google Play.

Up to nine searches a day can be made over a two, five or 10-mile radius, with each giving the five cheapest prices.

The web page has more information about the average price of petrol and diesel at the big four supermarkets and at motorway services. It also features 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