The Automobile Association says fuel companies have not passed on recent savings to motorists.
The association says the companies could have dropped prices at the pump for petrol by about four cents, as the New Zealand dollar climbed to record levels against the US currency.
The AA says diesel prices are also higher than they should be.
But Chevron, which markets the Caltex brand, says the AA is wrong and its prices have been as low as they could have been.
Brent crude oil on Friday was trading at $US111.06 per barrel.