Concerns over global economic growth, underscored by the present European sovereign debt crisis, have steadily eroded the price of oil, with expectations of decline in global demand.
New Zealand prices were just under $2.20 a litre a month ago, but are now down to about $2.05 in urban centres.
Since May 14, North Sea Brent crude prices have fallen from $US112 ($NZ144) a barrel to a low of $US96 ($NZ123.80) this week, before regaining a dollar yesterday.
AA petrol watch last week correctly predicted further fuel price falls should be on the way, with BP and Z Energy the first to move earlier this week.
"Finally, it seems that refined commodity prices are catching up with falling oil prices during the last two months," the AA said in a statement.
The AA calculated last week the imported cost of petrol had fallen a total of 16c per litre, and diesel 12c, since mid-March, so, despite the latest pump price reduction, a further petrol price cut should be expected.
