Petrol prices are being cut by 3 cents to just under $2.10 a litre for 91 Unleaded, sparked by a higher New Zealand dollar and lower costs for refined petrol overseas.
BP led the drop and said it also cut 95 Unleaded 3c to just under $2.18.
Diesel was cut 4c a litre to $1.50.9c a litre.
"So far in 2013, we've seen a steady decline in the cost of refined products, coupled with small but steady strengthening of the New Zealand dollar overall," BP Communications Manager, Jonty Mills said.
The New Zealand dollar was trading just above US84 cents this morning, close to its highest levels in the past year.
"This has brought us to the point of being able to pass on the benefits today so hopefully those customers that are still in holiday mode can take advantage," he added.
Mills pointed to falling oil prices across most markets over the last week and accelerating inflation in China as contributing factors.
"Inflation in China will likely see tightening of monetary policy which, while curbing inflation, will also curb demand and this has flowed through to market numbers. US debt talks are also putting uncertainty in the markets," Mills said.
Meanwhile, world oil prices have made further gains overnight, with crude supported by unrest in north Africa following an attack by Islamist militants on an Algerian gas field and amid fighting in neighbouring Mali, analysts said.
Brent North Sea crude for delivery in March climbed US73 cents to $US110.41 a barrel in late London trading on Thursday. Brent crude has been about the US$110 a barrel mark for several months.
New York's main contract, light sweet crude for February, gained $US1.05 to $US95.29 a barrel.
''The latest news of the attacks put a geopolitical risk premium into pricing'' of energy, said Victor Shum, an analyst at research group IHS Purvin and Gertz.
Prices were being supported also by indications of improving US crude demand.
A report by the US Energy Administration on Wednesday said American oil stockpiles dropped by one million barrels in the week to January 11.Analysts had forecast a build of 2.1 million barrels.