Drivers across the UK were punished at the pumps last month, as new analysis shows the cost of fuel rose again during July.
The RAC figures suggest the price of both petrol and diesel went up by around 1p per litre, after prices had fallen by around 2p during June.
At the end of July, the UK average for a litre for petrol stood at 128.8p, while diesel was 131.9p a litre.
The RAC called the latest rises further evidence that British motorists are being subjected to “roller coaster” fuels costs.
It now costs £7.50 more to fill a 55-litre unleaded tank than it did at the same point a year ago, equal to a 12% price hike.
The annual increase for diesel was even greater, with drivers forking out £8.77 more for a full tank of diesel compared to 2017, a rise of 14%.
The analysis shows that the biggest fuel price hikes were found at supermarket forecourts, cancelling out the much-publicised fuel cuts introduced earlier this summer.
News of fuel price hikes comes as many holidaymakers are choosing to hit the roads and head off on UK staycations this summer, as Britain bakes in heatwave temperatures.
The RAC also warned that a high degree of volatility in wholesale fuel prices means drivers could face further price fluctuations at the pumps.
RAC Spokesman Rod Dennis said: “July saw a return to rising prices at the UK’s forecourts, following some price cuts in the previous month – the roller coaster effect of rising and falling prices that drivers will have witnessed in recent months is certainly in full swing.
“The volatility of the price of a barrel of oil, and in turn wholesale fuel prices, makes it difficult to determine where prices might go next.
“What is certain, however, is how much more expensive it is to fill up a car this summer compared to last year.”
Drivers heading off on UK road trips this summer should check out our top tips for summer driving so that you can stay cool behind the wheel.