Petrol and diesel prices have fallen for the second month in a row.
Unleaded is down by some three pence a litre in June compared to May, while diesel fell by four pence a litre, according to the RAC.
However, the motoring organisation said prices remain too high and do not properly reflect the wholesale price of oil.
It has called on competition watchdogs to take action amid concerns that the margin between what retailers – including supermarkets – are paying for fuel and what they are charging drivers is too high.
The RAC pointed out that prices in England, Wales and Scotland are considerably higher than in Northern Ireland, where there is proper competition among petrol retailers.
It said the average price of petrol across the UK at the end of June was just under 145p a litre – down from 148p at the start of the month. Diesel dropped from 153.74p per litre to 150.13p.
The changes mean it now costs around £80 (£79.76) to fill up a 55-litre family car with petrol and £82.57 for the diesel equivalent.
The RAC said only drivers in Northern Ireland are getting a fairer deal at the pumps as a litre of petrol there sells for an average of just 140.5p – 4.5p cheaper than the UK average. Diesel is 142p – an incredible eight pence less than the UK-wide price.
The motoring organisation said there are big price disparities in terms of what the major retailers charge in different parts of the country.
For example, the difference between their cheapest and most expensive sites ranges from 6p for petrol at Tesco sites, to 10p at Morrisons, 13p at Sainsbury’s and 35p at Asda.
The RAC said petrol bought at the 535 sites run by oil giant Shell is the most expensive in the UK at an average of 149p – four pence more than the UK average and 8.5p more than in Northern Ireland. BP-operated forecourts are not far behind with an average of 146.5p.
Shell also has the highest average for diesel at 155p – 5p more than the UK average and a whopping 13p more than the average in Northern Ireland. BP’s average is 152p across the 287 sites it owns and runs.
RAC head of policy Simon Williams said: “While it’s good news prices at the pumps have fallen for the second month in a row, this also leaves a bad taste in the mouth because we know drivers in Great Britain are continuing to get a raw deal as both petrol and diesel are still much more expensive than in Northern Ireland.
“This month’s Fuel Watch report also reveals just how expensive fuel is when bought at forecourts owned and run by oil giants Shell and BP.
“We remain baffled how the very same fuel can be sold for such vastly different prices by the biggest retailers, whether they’re run by supermarkets or the world’s largest oil companies.”
He added: “Wholesale costs are still low enough to merit cheaper prices at the pumps. Looking at the fairer average prices charged in Northern Ireland, petrol should be 4.5p lower across England, Scotland and Wales and diesel should be a whole 8p less.
“We will continue to highlight this disparity, along with the massive differences between major retailers’ high and low prices.”
A new Pumpwatch scheme will provide drivers with real time information on fuel prices so allowing them to shop around and boost competition.
Average Fuel Prices Across the UK (price per litre)
Unleaded Average Min Max Difference
England 144.1 136.7 171.9 35.2
Scotland 143.4 137.7 154.9 17.2
Wales
Northern Ireland 140.5 136.7 144.9 8.2
Diesel
England 149.3 137.9 176.9 39
Scotland 147.9
Wales 147.
Northern Ireland 142.2 137.9 146.9 9.0
* Source RAC Fuel Watch
