Fuel prices fell by around 2p a litre in December, reversing some of the increases seen in November when unleaded went up more than 2p (2.2p) and diesel by almost 4p (3.8p), new data from RAC Fuel Watch shows.*
Petrol came down by 1.8p last month to 135.37p and diesel dropped 2.3p to 144.27p. This means both fuels finished 2025 about 1.5p lower than they began the year (petrol 136.85p and diesel 142.91p – 1 Jan 2025).
Throughout 2025 petrol has averaged 135.69p and diesel 142.96p which is 6.5p and 5.7p less than 2024 (2024 – 142.23p and 148.67p). Both fuels recorded year lows on 9 June, with petrol dipping to 132.03p and diesel to 138.14p.
Drivers choosing to refuel at a supermarket-operated forecourt saved themselves 3p a litre in December as unleaded sold for an average of 132.65p and diesel for 141.24p, both having come down 1.8p over the month. This equates to a saving of £1.50 a tank when filling up a 55-litre family car. A full tank of petrol at a supermarket costs £72.96, compared to the UK average cost of £74.45. The diesel equivalent is £77.68, versus £79.35.
Despite the slight downward shift in December, prices at the pumps haven’t followed the rate of fall seen in wholesale prices. Oil recorded its lowest monthly average price since January 2021 at $61.69, and at one point dipped below the $60-a-barrel mark, something which has not been seen since 8 February 2021.
In Northern Ireland the average price of a litre of petrol is currently almost 8p lower than across the whole of the UK at 127.5p and diesel is nearly 9.5p less at 134.9p, showing that drivers there get a better deal than those on the other side of the Irish Sea.
RAC head of policy Simon Williams said: “After prices at the pumps fell by 2p a litre in December drivers are starting the new year paying 1.5p less than they were a year ago.
“But with oil tumbling below $60 a barrel in mid-December and recording its lowest monthly price in six years, it’s a shame drivers aren’t seeing even lower prices on forecourts up and down the UK. As wholesale fuel costs went below those that led to the cheapest prices of the year in June, we’d have hoped to see the year lows of 132p for petrol and 138p for diesel beaten.
“We hope that 2026 will see more competitive pump prices on the back of the Government’s fuel finder scheme going live at the start of February and increasing competition.”
Drivers looking to get the best prices on the country’s forecourts should download the myRAC app for free from the App Store or Google Play. Users, whether RAC members or not, can search up to five times a day for the cheapest fuel over a two, five or 10-mile radius.
The online RAC Fuel Watch resource 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.