Motorists are paying well over market prices for diesel, the RAC has said, as it called on the government to take action to ensure more price transparency for consumers.
The RAC and other motoring groups have frequently warned drivers are paying a costly premium on fuel compared to low wholesale prices.
According to the recent RAC Fuel Watch analysis, diesel was 6p a litre cheaper than petrol on the wholesale market at the end of last month. The average price at the pump clocked in at 159.43p while petrol was unchanged at 146.5p.
Despite a 4p-per-litre drop for diesel during April, the report said prices in Northern Ireland, where there is a fuel price transparency mechanism in place, were at 147.47p.
The RAC said drivers should be paying around 143p “at the very most” for a litre of diesel.
Around 17.6 million vehicles licensed in the UK are diesel-powered, including the vast majority of vans. They represent 43 per cent of all vehicles on the road.
As is often the case, supermarket diesel is 2.75p cheaper than the national average, price while the figure stood at 3.5p for unleaded, the RAC said.
RAC fuel spokesman Simon Williams said: “We feel there should be an obligation on retailers to reflect wholesale price movements on their forecourts.
“Sadly, the only place this seems to happen is in Northern Ireland where a litre of diesel is, incredibly, being sold for 12p less than the UK-wide average.
“Our data shows that the average retailer margin on a litre of diesel is a shocking 22p a litre compared to petrol which is around 8p.
“The long-term averages for both fuels is 7p which means retailers are making three times what they have in the past for diesel. This is hard for them to justify and equally hard for diesel drivers to swallow.
“Action at a government level is badly needed to stop drivers being ripped off any longer.”
Gordon Balmer, executive director of the Petrol Retailers Association which represents independent operators, responded: “The independent sector accounts for approximately 36 per cent market share by fuel sale while the supermarkets are market leaders at 45 per cent.
“Due to their market share, supermarkets are price leaders and in many cases our members will use them as markers for pump prices when operating in the same area.
“This dynamic is now shifting, with many commentators noting that independent forecourts are increasingly offering more competitive prices.”
