After a month of surging prices, petrol and diesel are now nearly the most expensive they have ever been in the UK, according to the Automobile Association.
The AA says that petrol ended January nearly 1.5p a litre more expensive than it began it, at an average of 135p. The price of diesel rose more slowly, but at a national average of 142.8p a litre, it is now just 0.2p below its highest ever average price, which it reached in May 2011.
According to Citywire.co.uk, this means that the average family running two petrol cars is paying nearly £6 more to fill their tanks than a month earlier.
"What's more," the AA points out, "petrol prices would have been another 1.5p higher had the pound not strengthened against the dollar in the last month."
But, it added, rising oil prices – driven largely by sanctions against Iran, the world's fourth largest oil producer – are now cancelling out the effect of the stronger pound, leading to high pump prices.
Northern Ireland has the most expensive fuel in the UK, at 135.9p for a litre of petrol, and 143.5p for diesel. Meanwhile, prices are lowest in the north of England, at 1.7p and 1.2p a litre respectively lower than across the Irish Sea.
Edmund King, AA president, said: "In a period of stagnant wages, petrol costs 23p a litre more and diesel 29p a litre more than in February 2010, when fuel price rises picked up pace."
"A typical 50-litre petrol refill now costs £11.50 more and filling an 80-litre commercial van tank with diesel has risen £23.20," he said.