Tauranga motorists are being advised to keep an eye out for lower fuel prices.
Service stations in parts of the North Island are discounting petrol costs, in some cases, 91 octane petrol is being retailed for $1.60 per litre, more than 30 cents below average.
"New Zealand does not have a single national fuel price, and with most service stations being independently-owned, the owners can set their own price," said AA PetrolWatch spokesperson Mark Stockdale in a statement.
"Even company-owned stations will adjust prices locally to match competition," he said.
After prices climbed 16 cents per litre during February, petrol continued to rise during March before falling later in the month, ending on $1.92 per litre for 91 octane at most outlets.
Diesel prices fell 2 cents in March to $1.20 per litre in the North Island's main centres.
"Despite the increases of the last few months, retail prices are still the lowest in over four years," said Mr Stockdale.
The AA said if service stations displayed the price of premium fuels on their price boards, it would improve premium petrol price competition and consumer choice.
"If you use premium grade petrol, check the price on the pump - even if the price of petrol is being discounted, it often only applies to 91 octane and not premium grades." said Mr Stockdale.
AA also said they want the Government to make it mandatory for service stations to display the price of all fuels on the price boards.