The roadside recovery company said the wholesale cost of petrol has fallen by 20p since the start of June. However, UK retailers continued to increase their prices in June and only reduced their pump prices by an average of 9p in July, the company added. The RAC said the wholesale cost of unleaded – the price when petrol reaches forecourts – has now fallen back to its early May price of 131.75p per litre, which has led to average pump prices of around 167p per litre. But drivers are currently paying an average of 183p per liter at the pumps across the UK despite a cut in wholesale costs, the RAC said. This means they could be paying almost £9 per tank more than they should. The RAC also said drivers will now have to pay around 182p per liter for diesel – almost £6 per tank lower than the end of July average of 192p per litre. Tesco, Asda, Morrisons and Sainsbury’s, known as the ‘big four’ supermarkets, have faced criticism along with several other suppliers for failing to cut prices in line with falling wholesale costs. The RAC said that while a number of retailers cut their prices last week, the cuts were not enough to be in line with wholesale costs. The warning comes after fuel prices hit their highest levels earlier this summer as the UK’s cost of living crisis began to worsen. RAC fuel spokesman Simon Williams said: “July has been an unreasonably difficult month for drivers due to the reluctance of the big four supermarkets to reduce their prices to a more reasonable level, reflecting the ongoing and significant reductions in the wholesale cost of gasoline and diesel. . “As it was, we saw independent retailers leading the charge with fairer pump prices appearing across the country, which ultimately forced supermarkets to finally implement a more substantial reduction late last Friday afternoon. “What should have happened is that the major retailers cut their prices more significantly on a daily basis, given that the wholesale price of gasoline has fallen steadily over the past eight weeks.” Use Chrome browser for more accessible video player 2:40 BP reports £7bn profit Read more: UK has done less to ease burden of high petrol prices than other nations in Europe, figures suggest Nine tips to reduce how much petrol or diesel you use amid record fuel prices ‘People are desperate’ – the dramatic increase in failing businesses Mr Williams advised drivers to stop thinking of supermarkets as the cheapest places to get fuel. He said motorists should “shop around as you are very likely to find an independent retailer that does the right thing and fairly reflects their lower wholesale costs by charging a lower price”. He added: “This is really encouraging because independents buy new stock less often than supermarkets as they don’t sell as much, and therefore are not as well placed as their competitors to buy fuel at lower prices when available sudden falls in the market”. A spokesperson for Sainsbury’s said: “We are committed to offering motorists great value and over the weekend we reduced the price of petrol and diesel in our forecourts. We price locally and competitively.” Sky News has contacted Tesco, Asda and Morrisons for comment.