Motorists already soaking up record petrol prices in New Zealand will have to wait and see if they go up further after global crude oil prices hit 15-month highs this week.
The higher New Zealand prices are up partially because of the weakening New Zealand dollar and recent Government tax increases, while the global oil prices hit a 15-month high point, being boosted by signs of strengthening US demand and ongoing supply fears linked to the political situation in Egypt.
The AA, which disputes the latest price rises, said prices in Auckland, Wellington and Christchurch were 91 octane, $2.27 per litre, 95 at $2.35 and diesel at $1.57.
AA senior policy analyst Mark Stockdale said yesterday petrol's price had now reached an all-time high, with BP having raised pump prices 4c per litre, and diesel 3c on Thursday.
He said when contacted it was not yet clear if the higher crude prices would immediately flow through to the separate refinery prices, which have a more immediate impact on retail prices.
''This week's rise in [global] crude prices could be offset by the foreign exchange rate. I'd expect the fuel companies to hold off any more rises until they see what the kiwi does,'' he said.
In earlier trading, New York's main contract, West Texas Intermediate for delivery in August, spiked to $US107.45 ($NZ136.18) a barrel, a level last seen in late March 2012, then eased back, AFP reported.
Brent North Sea crude for August rallied to $US108.93 a barrel, reaching a high last seen in early April 2013, before pulling back to $US107.46.
Mr Stockdale said since the July 3 retail price rise, commodity prices had risen further, up $US5 per barrel for petrol, although diesel is only up $US1 a barrel.
However, the strength of the kiwi had also increased ''slightly'', and the AA's analysis showed that since last Wednesday, the imported cost of petrol has only risen 2.7c per litre, while petrol margins are only down 2c, with no increase in the cost of importing diesel, and no decrease in diesel margins.
''With signs that the NZ exchange rate is recovering, now around $US79c, we say the latest increase is too much, too soon,'' Mr Stockdale said.
Diesel prices are still well below the July 2008 high of $1.92 a litre because diesel commodity prices were higher then, and so were petrol commodity prices, he said.
''But retail prices are higher today because tax on petrol has risen 17c per litre since 2008, whereas there is no tax on diesel except GST,'' he said.
Crude futures had already scored multi-month highs on Wednesday after the US Energy Information Administration's (EIA) weekly crude stockpiles data indicated a major lift in energy demand.
The EIA said crude-oil stockpiles tumbled by 9.9 million barrels in the week ended July 5. That was more than triple the 2.9-million-barrel drop expected by analysts polled by Dow Jones Newswires, and followed the prior week's drop of nearly 10 million barrels.
As well, traders remain deeply concerned over potential disruption in Middle East supply following the overthrow last week of Egypt's Islamist president Mohamed Morsi.
Egypt is not a major crude oil exporter but is home to key oil transit points of the Suez Canal and the Sumed pipeline.
''The spike in oil is driven by three things; optimism over improving economic conditions in the United States, fears of escalation in Egypt's unrest, and lower US inventory levels,'' analyst Ishaq Siddiqi at trading firm ETX Capital said.
''Commodities are also tracking stock markets higher today, climbing for the eighth day and heading for their best run since 2010 after Bernanke unexpectedly said the US economy will need highly accommodative monetary policy for the foreseeable future, fuelling hopes that the end of QE [quantitative easing] is not nigh.''
- Additional reporting from AFP.
