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.