Only time will tell if these reductions will be passed onto the consumer.
Yesterday, the price of a litre of 91 petrol ranged from 170.9c to 174.9c, before lunch in Whangarei.
Mobil was the cheapest with 170.9c, but BP had the biggest decrease at 17 per cent, since raising their prices to 209.9c per litre in July 2014.
Kaitaia saw on average a 15 per cent reduction in prices since July 2014, ranging from 188.9c to 190.9c per litre, and in Kerikeri both BP and Caltex priced 91 petrol at 189.9c.
Outside Mobil on Walton St in Whangarei, motorists filling up spoke to the Northern Advocate about the effects of the lower petrol price.
Poet Sam Hunt said he was aware the prices were the lowest in over four years but he has not yet benefited from the savings.
"I can't say I'm drinking better wine as a result," Hunt said.
Gary Corkin said he is now less reluctant to take trips in the car and will be "eating" his savings.
"I'm going to use the money to eat better," he said.
Farmer Tracey Jenkins said she will be taking advantage of the cheaper petrol prices.
"We'll fill up extra cans and stash them away."
Northland motorists are benefiting from the cheapest petrol prices in the country due to "The Gull Effect", AA PetrolWatch spokesperson Mark Stockdale said.
"Wherever Gull operates they'll have the lowest prices. If it wasn't for Gull the others wouldn't cut their prices," Mr Stockdale said.
However, he said petrol companies are not being generous enough with price cuts as commodity prices sometimes go down by more than two cents at a time.
New Zealand has seen a record 16 petrol price cuts in a row in the past few months, something that did not happen in 2008 when oil prices plummeted, Mr Stockdale said.
"Eventually it will have to bottom out, and the question is will it stay at a low price or will it reverse and start going back up?"
He said people should make the most of the low prices - but be cautious.
"If you're thinking about going out and buying a V8 because the price of petrol has gone down, that would be ill advised."