The price of diesel has had its biggest monthly fall in more than a year, new figures show.
UK motorists were charged an average of 119.5 pence per litre (ppl) at the end of March compared with 122.2ppl at the start of the month, according to RAC Fuel Watch data.
This is the most significant decrease since January 2016 and was caused by a 5% fall in the price of oil over the same period, the motoring firm said.
Unleaded also became cheaper during March, falling from 120.2ppl to 117.5ppl.
Several supermarkets made a pair of two pence per litre fuel cuts last month, winding back prices to a similar level to the start of the year.
RAC fuel spokesman Simon Williams said: "With longer days and the prospect of warmer weather, many motorists will be making some longer journeys so lower fuel prices are very welcome.
"But the big question is what will happen as we move towards the summer.
"Everything really hinges on the oil market and whether more is done to curb supply with a view to getting the price to rise.
"The Organisation of the Petroleum Exporting Countries (Opec), together with some non-members, have cut production, but their efforts have been undermined by the US ramping up its fracking production."