The price of petrol fell six times during June, the most consecutive price cuts since 2008.
The price of a litre of 91 octane fell 19 cents during the month, down to $1.97 a litre in the main centres, the first time it has dipped below $2 since last August.
The price of diesel fell five times, and 13 cents, to end the month on $1.41 a litre at most outlets.
AA PetrolWatch spokesman Mark Stockdale said the decreases were caused by ongoing falls in global commodity prices and a stronger Kiwi dollar.
"The run of price cuts is a welcome reprieve from near-record fuel prices, and comes just in time for the school holidays. The AA calculates the average motorist will be saving about $9 per fill of 40 litres compared to just over a month ago.''