Every mile driven in the UK now costs an average 18.5p for petrol and 20p for diesel, according to new RAC Fuel Watch data.
April saw a break in the cycle of increasing price rises at the pumps after three months of fuel costs climbing to new record levels.
The average price of petrol dropped by 0.5p to 162.75p a litre in April while diesel remained unchanged at 177p.
Petrol is now 4.5p a litre lower than the record high of 167.3p seen on 22 March while diesel is 2.5p below the high of 179.9p recorded on 23 March.
Filling a 55-litre family car from empty now costs 50p less than at the start of the month at £89.51, while diesel still costs £97 for a full tank, according to the RAC.
The average price of a litre of fuel at motorway service stations rose by nearly a penny a litre in April with petrol going up 0.67p to 182.08p and diesel 0.83p to 192.34p.
Asda offered the lowest priced petrol at the big four supermarkets at 159.38p, closely followed by Morrisons and Sainsbury’s (SBRY.L) which both clocked in prices under 160p. Asda also had the cheapest diesel at an average of 173.12p across its sites – half a penny lower than Morrisons.
Petrol and diesel prices at the pumps are governed by wholesale fuel prices, which in turn, are affected by several factors including the global price of crude oil, supply and demand for crude oil, distribution costs, and the pound to dollar exchange rate as refined fuel is sold in US dollars per metric tonne.
While the price of oil dropped under $100 three times in April the barrel price finished only slightly higher than it started the month at $108.62, compared to $107.52 on 1 April.
However, the pound (GBPUSD=X) to dollar exchange rate dipped, falling from $1.30 to $1.25 over the month, raising the price of wholesale fuel.
The margin fuel retailers decide to take also affects the price of fuel. Retailers took 4p more per litre in April than they did in March.
RAC fuel spokesman Simon Williams said: “Although the price of oil has cooled considerably, there’s still plenty of uncertainty in the market which is leading to prices jumping around a lot. This coupled with the exchange rate worsening isn’t good for drivers and news that the EU is planning to phase out Russian oil is likely to cause the barrel price to rise.
“However, retailers really should have passed on the savings they were benefitting from when wholesale prices were lower earlier in April; sadly for drivers this didn’t happen. Instead, the biggest retailers, which buy most frequently held out, protecting themselves from future rises.
"They will no doubt feel they were justified in not lowering their forecourt prices as wholesale costs are now rising again, in part due to the pound losing ground on the dollar, making it more expensive for retailers when they buy new stock.
“It’s also very much the case that retailers’ margins were far higher in April than they were in March. RAC Fuel Watch data estimates they took around 4p more a litre than they did over the course of the previous month. This will surely be a disappointment to the chancellor who cut fuel duty by 5p a litre in the Spring Statement.”