Diesel prices have seen their largest ever drop according to the RAC.

The average price fell by 12p a litre in May, from 158.91p to 146.99p. This cuts the cost of a full 55-litre family car fill-up by £6.50.

Meanwhile, petrol prices reduced by 3p from 146.35p to 143.26p – a saving of £1.70 a tank compared to the start of the month.

Sunshine and savings

May was the seventh consecutive month in which pump prices fell. This means diesel is now 52p lower (£28.60 a tank) than the all-time high of 199p last summer.

Over the same period, petrol is 48p lower (£26.40 a tank) than its record of 191.5p.

All this comes on the back to criticism by the Competitions and Markets Authority (CMA) that highlighted how fuel retailers, particularly supermarkets, had failed to pass on the drops in wholesale prices.

Pressure points

“After calling for big pump price cuts for weeks we were pleased to see that May was the month where this finally happened,” states RAC fuel spokesman Simon Williams.

“The fact it appears to have been prompted by the Competition and Markets Authority’s mid-month announcement about weakening competition in fuel retailing is surely not a coincidence.”

In Northern Ireland, diesel is just 138.49p – 8.5p lower than the average across the whole of the UK. The RAC believe this highlights the fact that there is still more that can be done by retailers to cut fuel costs.

Free markets

Supermarkets are clearly important players in the price drops. They brought their diesel prices down by nearly 14p a litre (13.73p) to an average of 142.96p.

However, they only shaved 2.4p off petrol (142.96p to 140.57p).

Williams states: “What’s happened to the price of diesel in May will no doubt give the CMA something to think about.

“We strongly hope the pump price reductions continue as they should.

“ If greater transparency returns to the market, we ought to be heading for an average diesel price of 137p,” adds Williams. “A price the UK as a whole hasn’t seen since September 2021.”