And the fall does not include the very latest 2p-a-litre petrol reduction by the four biggest supermarkets which took effect on Wednesday.
The AA said that between mid-November and mid-December UK average petrol prices fell 6.6p to 116.32p a litre.
Only the October-November 2008 fall of 11.5p a litre and the August-September 2006 dip of 7.9p have been greater than the most recent decline.
The AA also said that average diesel prices have fallen 5.27p a litre to 122.16p over the mid-November to mid-December 2014 period.
Currently, south west England has the cheapest petrol, at an average of 116.1p a litre, while East Anglia has the dearest, at 117.1p.
The cheapest diesel is to be found in Northern Ireland, at 121.8p a litre, with the most-expensive in Scotland, at 122.7p a litre.
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The RAC has suggested the new year could usher in petrol pump prices below £1 but the AA said this possibility remained “remote”.
AA president Edmund King said: “A 6.6p-a-litre drop in the price of petrol releases a potential £3 million-a-day switch of consumer spending from fuel forecourts to other businesses.
“It will also lower the cost of transporting goods, hopefully also to be passed on to customers.”
Mr King went on: “However, the parallels with the 2008 crash, albeit that was a market in freefall while this one has been engineered by Opec and could be stopped any time, carry a warning from the ghost of Christmas past.
“In 2009, a new year brought a new assessment of the market and pump prices started to rise again on January 5.”
Asda, Sainsbury’s, Morrisons and Tesco have all reduced their petrol by 2p a litre and their diesel by 1p a litre.
The Asda cut means its customers are now paying no more than 110.7p a litre for petrol, with the company’s diesel costing 117.7p a litre.
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