Petrol and diesel prices have jumped 30p per litre in the last year, soaring by nearly 8p in the last month alone.
Both fuels reached record prices in October following 10 consecutive months of increases.
The latest rises meant that an average petrol-powered family car cost £4 more to fill up at the end of October than at the start, while a diesel tank was £4.50 more expensive.
And both fuels were a massive £16.50 more expensive for an average tankful than in October 2020 - a 26% increase.
The increase has been driven by rising oil prices but while increasing crude costs have pushed up wholesale fuel prices by 5p and 4.5p for petrol and diesel respectively, retailers have put prices at the pumps up by 7.5p and 8p.
According to RAC Fuel Watch, the UK’s “big four” supermarkets remained the cheapest places to buy fuel, despite adding more than 9p onto the price of a litre of unleaded and more than 10p onto diesel.
Asda had the cheapest petrol at 140.98p per litre, only slightly lower than Sainsbury’s at 141.68p.
Sainsbury’s, however, offered the lowest price diesel at 144.37p, just slightly less than Asda which charged 144.57p at the end of October.
In stark contrast, motorway services remained the most expensive places to fill up. The average price of motorway petrol was 158.43p on 31 October while diesel reached an all-time high of 163.08p.
Across the UK petrol prices varied by almost 3p while there was a gap of more than 4p between the cheapest and most expensive regions.
Drivers in Northern Ireland enjoyed the cheapest petrol and diesel, at 142.1p and 144.36p per litre respectively.
At the other end of the scale, those in England’s South-East faced the highest bills, with petrol 144.92p and diesel 148.55p.
RAC fuel spokesman Simon Williams said October had been a “horrible” month for drivers but there might be a period of stability ahead.
He said: “With a fill-up costing £16.50 more than a year ago, the impact is definitely being felt in homes up and down the country. It’s also bound to have a negative effect on the economy.
“There is, however, a glimmer of hope that the oil price may have peaked for the time being, but much will of course depend on whether more supply is released when oil producer group OPEC+ next meets on Thursday.
“Regardless of this, the profit margin retailers are taking on each litre of petrol is greater now than it used to be prior to the pandemic, which is artificially making forecourt prices higher, particularly as VAT is charged on top. We urge the biggest retailers, in particular, to play fair with drivers and ease the burden at the pumps by lowering their margins on petrol from around 8p a litre to more normal levels.”