Diesel users are being stung by petrol stations failing to pass on the falling cost of wholesale prices, a new report from the RAC has claimed.
In total, the RAC estimates diesel users have overpaid as much as £1.3bn since the start of the year due to this foot-dragging.
Diesel on forecourts costs 10% more on average than petrol even though the wholesale price is lower currently, said the motoring organisation.
According to its estimates, forecourt owners are making double the profit from diesel users on average compared to petrol buyers.
Often these are small businesses that use vans and trucks to keep their businesses running so have no choice but to pay, the RAC added.
In a statement, Steve Gooding, director of the RAC Foundation, said: “The wholesale price of the fuel is now below that of petrol yet still costs 15p a litre or so more at the pumps, much more than the historical gap of between 5p and 10p.”
An average lite of diesel costs 160.7p, according to its data, compared with 146.91p a litre for petrol.
That equates to a profit per litre of about 22.36p for diesel against 9.16p a litre for petrol.
Gooding warned that as diesel users are mostly businesses, the extra costs often just get passed through to customers.