Drivers are still paying over the odds for fuel despite another 7p drop in prices last month, according to new research.
Although petrol and diesel prices fell significantly in September, retailers have been accused of swelling their profit margins at the expense of drivers.
The RAC estimates that motorists have been denied a further 10p per litre cut in petrol prices as retailers fail to pass on the latest reduction in wholesale fuel costs.
Petrol prices fell by nearly 7p per litre to 162.89p per litre - the sixth biggest monthly drop since 2000. However, the RAC says that given continued reductions in wholesale prices, petrol should be around 152p. It says instead of passing these reductions on, retailers have stretched their profits from around 7p per litre to 17p.
Fuel prices have been falling since early July, when they reached all-time highs of 191.53p for petrol and 199.09p for diesel. Drivers are now paying around £16 per litre less for an average full tank of petrol in early July and around £10 less for a full tank of diesel, which fell 3.5p per litre in September.
RAC fuel spokesman Simon Williams said: “Despite September seeing the sixth biggest ever drop in the price of petrol drivers really should have seen a far bigger drop as the wholesale price of delivered petrol was around 120p for the whole month. This means forecourts across the country should have been displaying prices around 152p given the long-term margin on unleaded is 7p a litre.
“In stark contrast to this RAC Fuel Watch data has shown margins to be around 17p a litre – a huge 10p more than normal. And the average price of petrol at the big four supermarkets is only 1.5p lower than the UK average – less than half what it usually is which points heavily to them not playing fair with drivers.
“This is backed up by the fact that Morrisons, which was charging an average of 162p a litre for petrol at the end of September, is currently running a 5p a litre off promotion for customers spending £40 in store. This type of promotion tends only to be seen when supermarkets are benefitting from lower wholesale prices.”
Mr Williams advised drivers to shop around for fuel and not assume that supermarkets were always the cheapest sites, with some small independent forecourts undercutting larger rivals in recent months.
He also warned that with the pound’s precarious position against the dollar and the potential for the OPEC nations to introduce new restrictions on oil production it would not take much for petrol and diesel prices to start rising again.