It's the seventh significant price cut in a fortnight, the AA said, but not all motorists are enjoying the benefits.
AA Petrolwatch said fuel company margins were "so high that fuel companies can still afford to cut pump prices by 5c a litre or more".
Although fuel in some inaccessible or rural areas was always more expensive than in cities, the AA said, people in some of those locations could be forking out for excessively high premiums.
Prices were still well above $2 a litre of 91 in some areas such as the alpine South Island and Waiheke Island where there are supply issues. Areas with a small customer base were most likely to miss out on price cuts.
"What a lot of people forget is the price we pay is a function of volume," AA senior policy analyst Mark Stockdale said. "So the more fuel you sell, the lower the price can be, because your overheads are spread over a larger volume."
The best prices were usually at busy stations close to major transport routes, where the cost of bringing in fuel was lowest.
"When you go to remote locations, not only do you have higher transport costs to get fuel to those remote locations, they also tend to have small populations," Mr Stockdale said.
People in these areas should not be paying 30c a litre more than their urban counterparts, he said.
In Wellington, Emily Cranfield, territory manger for a distribution company, said the cost of filling up her Toyota RAV4 had plunged. She spent around $80 when she filled up recently; only a few weeks ago, it had cost around $100.
Her friend Jess Molloy, a graphic designer, said she often used public transport, and was still waiting to see plunging prices have an impact on fares.
"Public transport prices have been going up and up and up."
