A decline in the New Zealand dollar to six-year lows has driven the fourth petrol price rise in just over a week, the AA says.
Mobil, BP, Shell and Caltex today increased the price of 91 unleaded petrol by 5c to 152.9c a litre, and 95 octane to 157.9c a litre.
Gull was not raising prices today, but would review them tomorrow, a spokeswoman said.
Diesel was unchanged.
The price of petrol has risen 20c since January 14.
"We certainly are disappointed with the latest increase which is the fourth in eight days, which is basically due to the decline in the exchange rate," AA spokesman Mark Stockdale said.
Last week's two 5c increases were due to the rise in the price of refined oil, which was moving in the opposite direction to crude oil. The price of refined oil has risen nearly 50 percent since the start of the year, Mr Stockdale said.
Price increases on Tuesday and today reflected an US8c fall in the New Zealand dollar, making it more expensive to import petrol.
The AA monitors the importer margin, which was still below average despite the recent petrol price rises.
The refined diesel price had also risen, but the margin was still comfortable despite the falling exchange rate.
Refiners had cut output globally in reaction to a low refining price, and reducing supply had increased the price.
"It is possible that now that the refined price has recovered for them to a much more comfortable level that it may settle - it's quite possible that it may even drop back a bit," he said.
"But what we're really dependent on is actually the exchange rate not falling, and preferably it has to climb to see a reduction in the pump on petrol."
The kiwi hit a six-year low of US51.65c yesterday.
