This will be a relief to southern motorists taking to carpooling and public transport as a result of fuel hikes from the United States-Israel war on Iran.
The national average for 91 was $3.27 per litre and $3.12 for diesel yesterday, tracked by fuel price app Gaspy.
Overseas data monitored by the Automobile Association (AA) indicated gaps evening out between crude oil and refined oil prices.
AA principal policy adviser Terry Collins said average petrol prices for 91 regular would likely drop below $3 per litre this month and diesel prices would ease if there were no major changes to the Strait of Hormuz.
This comes despite a US-Iran ceasefire appearing to hit yet another hurdle after reports a furious US President Donald Trump demanded Israel stop a major raid on Lebanon to prevent Iran leaving the negotiating table.
Lower prices would be more certain once there was two-way shipping traffic in the strait, he said.
Lower demand from high prices internationally was balancing a market now able to access cheaper refined product.
‘‘I was going to fill up my car with gas today and I might just do half a tank because I think it will be cheaper next week.’’
Gaspy showed the price of 91 was already as low as $2.90 per litre in Epsom and $3 was the cheapest in Wellington, with strong competition between fuel stations.
‘‘Three weeks ago we wondered when will it be there again and it was hard to pick, but it looks like we are here now.
‘‘And the data that I have got still says the margins are up fairly high so we should expect some more price reduction over the next two weeks so that is good news coming.’’
Lower prices could flow through to the end of the month, he said.
‘‘But it only takes a ceasefire to be broken or one party to not negotiate and that prediction goes out the door.
‘‘What we need is some sustained ceasefire that occurs in the strait and the opportunity for those boats to leave it.
‘‘And the real indicator is the willingness of those shippers to bring those boats back into the strait.’’
Australian Institute of Petroleum data shows the market price for diesel per barrel has gone from about $US180 at the beginning of last month to $US137 last weekend.
Mr Collins said there was better alignment between crude oil and refined product prices after diesel prices at one stage reached $US350 a barrel ($NZ589), before rapidly dropping after a ceasefire to about $US200 ($NZ337).
Without an oil refinery New Zealand relies on nearly half of its refined oil from South Korea, a third from Singapore as well as supply from Malaysia and other countries.
AA members had observed fewer vehicles on the road as drivers reduced trips and shorter travel times from less traffic, Mr Collins said.
‘‘There is definitely an uptake in public transport where that is available and I know in the town I am in people are doing things like car pooling with the ladies off to do their pilates taking three in a car now instead of three cars. ... Suddenly with public transport particularly people with gold cards are going in the middle of the day and getting it for free.’’
Demand was less elastic for diesel vehicles, but transportation of agricultural and primary goods had reduced over winter.
The AA has put out a new Trip Tracker app so motorists can work out the cost of a journey.
Australian fuel prices are much lower with 91 petrol at about $A1.77 ($NZ2.14) per litre in Melbourne at the weekend.
Mr Collins said Australia had a stronger dollar, lower goods and sales tax and the government had responded to high prices by cuts to fuel excise duty which had increased the price disparity between the two countries.
New Zealand drivers pay a fuel excise duty of about 70c a litre at the pump, about 6c for ACC, about 11c for emissions trading and 15% GST.
