Producers of crude oil, owners of oil refineries and the New Zealand government are among those making more money as the price of fuel hits a record high at the pump.
According to gas price comparison app Gaspy, the average price of 91 fuel is $3.60 a litre, and diesel is sitting about $3.23.
An investigation by The Guardian in August found eight of the biggest oil companies amassed profits of more than $US90 billion ($NZ159.8b) in three months as the US-Iran conflict sent energy prices soaring.
Energy expert and former Marsden Point refiner manager David Keat told Morning Report there were a few parties cashing in for different reasons.
"Anybody who's producing crude is doing very, very well in terms of windfall profit. They're getting probably the biggest share.
"The second group would be anybody who has an oil refinery, they're making extraordinary refining margins in this period."
The New Zealand government was also an "honourable mention".
"Because of course, if the price goes up, they still charge 15% of that price as GST, so they're doing all right."
Keat said oil refineries and producers were the ones that profited the most but it was not the well-known companies such as Mobil, BP or Shell that were making the highest sum.
He said these companies produced only around 12% of the world's crude oil.
"The big players are all the state-owned oil companies or state-affected, like the Russian and Chinese oil companies are state-influenced... European countries, and they all have a national oil company. So Saudi Arabia, UAE, but also Nigeria, Guyana, other countries. All those national oil companies are making a huge amount of money."
In response to a global increase to fuel prices, US President Donald Trump recently struck a diesel deal with Russia who is set to supply 300,000 tonnes of diesel now, with more later, to the US and global markets.
Keat said this was about 2% of one day's global demand.
"The market will just look straight through it. Even the 3 million tonnes that he's talked about coming at some stage is about a quarter of one day."
He said this was "smoke and mirrors" and there was no net increase in diesel supply.
"The Russians haven't suddenly got more diesel. Even if they're bringing down the reserves, that would be short term and at the expense of the Russian people themselves."
Keat said predicting where oil prices would go from the recent spike was difficult but there were some trends in the US Iran war, which appeared to be in a "stalemate".
"They've been very, very careful not to destroy any more oil infrastructure. If they do that, then really all bets are off."
"This is going to carry on, obviously, through the midterms. You can see the Iranians may well want to keep the pressure on Trump. So that could go on for another year or two until he's out of office."
Keat said a mitigating factor was that oil production outside of the Gulf was slowly growing as the world adjusted.
"The oil system will slowly come into balance."
"New Zealand, sadly, doesn't have an oil refinery anymore. So we're kind of at the mercy of the international markets."
Keat said the answer was actually pivoting to non-hydrocarbon sources for electricity, including electric vehicles.
