The average price of petrol rose for the second month in row in March with the possibility of further rises in the coming weeks.

Petrol prices rose for a second consecutive month in March

The RAC Fuel Watch figures show a litre of petrol went up by 2p in March to 122.58p. The average price of diesel also increased but only 0.70p. This is the second straight monthly increase for both fuels, making unleaded 2p more expensive than it was at the same time in 2018 and 2017 (120.11p – 2018; 120.15p – 2017).

Diesel, however, is nearly 8p dearer (122.82p – 2018; 122.19p – 2017), or £4.30 a tank. But the current price of petrol is still 8p a litre cheaper than it was in October last year (131p), which was the highest price seen since July 2014, and diesel is also 6p cheaper than it was in October (136p in October).

The pump prices follow a 4% jump in the cost of oil from $63.81 to $68.07 and a 2% drop in the value of the pound against the dollar ($1.32 to $1.30) – the worst possible combination for motorists.

The increase in the wholesale cost of petrol, which equated to 6.5p in March, started to be passed on by the supermarket fuel retailers immediately. This led to a litre of supermarket petrol going up 1.7p in March to 118.59p and a litre of diesel rising 1.27p to 127.48p.

Asda and Sainsbury’s both raised their prices by 2p a litre in the month. Asda, however, began a series of almost daily rises from late February, making for a 3.6p litre hike by the close of March (113.7p – 21 Feb to 117.31p – 31 March).

Asda’s increases, which weren’t mirrored by the other three major supermarkets, mean that the gap between the country’s cheapest fuel retailer on petrol and the other supermarkets has closed. From the end of October until the end of February the other three supermarkets were charging around 3p more for a litre of petrol than Asda but this has now closed again to the customary 1p to 1.5p.

Commenting on the outlook for the coming weeks, RAC fuel spokesman Simon Williams said: “Throughout March the wholesale price of diesel was on average 6p a litre more than petrol. This gap has now closed which should hopefully bring some relief to drivers of diesel vehicles. If retailers play fair with motorists the price of the fuel should fall by around 3p a litre in the next fortnight whereas petrol looks like it’s set to rise further with at least a penny or two likely to go on in the coming weeks.”