June saw diesel and petrol prices plummet, thanks to the increasing likelihood of an end to the war in Iran.
Diesel fell by an average of nearly 17p per litre to 167.14 ppl, the largest drop in a single month since 2000.
The average price of petrol also fell by an average of 8p a litre in June – not quite as dramatic as diesel, but still the seventh steepest monthly fall in unleaded in more than 26 years, from 159.37ppl to 151.40ppl.
The pump price reductions were driven by a barrel of oil sliding from $94.98 at the start of June to just $72.92 on June 30, on the back of a deal between the US and Iran to end the war.
The diesel pump price drop was even greater at the big four supermarkets with their average price coming down 19p a litre from 182.37ppl to 163.28ppl.
The unleaded reduction, however, was slightly smaller than the UK-wide one, at 7p (7.15p).
RAC head of policy Simon Williams said: “While diesel dropping 17p in a month is very positive, it’s also important to realise that its average price shot up 49p a litre from the end of February to 191.54p on 15 April, which equates to a rise of more than a penny a day. So, the cost of the fuel today remains far higher than it was at the start of the war.
“Fortunately, the oil price is now in the low-$70s range which is only $10 above the average of the first two months of the year”, said Williams.
“At the time the conflict began drivers had average prices of 132ppl for unleaded and 142ppl for diesel. As things stand, petrol should dip under 150p soon and diesel ought to get to below 160p, but we would need the price of oil to fall further to see a return to the pre-conflict prices,” he said.