DECEMBER saw the average price of fuel fall by 9p a litre – saving drivers £5 a tank – but drivers should have seen even greater drops, according to the RAC.
RAC Fuel Watch data shows petrol fell by 8.4p last month to 151.06p, making a full 55-litre tank for a family car £4.63 cheaper (£83.08).

Diesel came down by 9.4p to 173.97p, meaning a complete fill-up was £5.19 less than it was at the start of the month, at £95.68.
Unleaded bought at one of the big four supermarkets reduced by 10p a litre from an average of 157.86p to 147.76p and diesel by 11.4p from 181.66p to 170.23p.
Wholesale prices, which have fallen considerably since mid-October, remained largely unchanged, with petrol averaging 106p a litre throughout December while diesel was 123.4p.
Based on these wholesale prices and allowing for a 10p-a-litre retailer margin – 3p more than the long-term average – the RAC believes petrol should be being sold around the UK for 140p – 11p less than the current UK average.

For diesel drivers, the figure should be nearer to 160p a litre – 14p lower than the average at the end of 2022.
RAC fuel spokesperson, Simon Williams, said: “On the face of it, December looks like it was a good month for drivers with 9p coming off at the pumps on top of November’s 6p, but there’s no question that the drop should have been far bigger given how far wholesale prices have come down.
“For weeks we’ve been calling on the big four supermarkets to cut their prices more substantially to give drivers a fairer deal when they fill up, so even though they have reduced their prices collectively by more than 10p a litre in December, they are still nowhere near where they should be given the scale of the drop in wholesale prices.
“We hope the Business Secretary’s intervention just before Christmas puts more pressure on larger retailers to do the right thing.”
He said prices in Europe were ‘considerably cheaper’ thank in the UK.
“In fact, when compared to the 27 EU countries, we currently have the second most expensive diesel and the sixth most expensive petrol,” Mr Williams added.