Wellington residents pay the most for fuel in the country, according to the Commerce Commission's new fuel monitoring report.
The commission's second quarterly report for the three months ended 30 September 2022 showed motorists in Wellington, Porirua and Lower Hutt pay the most for regular 91, premium and diesel fuel.
Christchurch drivers got the best bang for their buck in petrol prices, while Tauranga offered the cheapest diesel, with both regions having the lowest average fuel prices.
Commission chair Dr John Small said the report showed significant fuel price variations across the main centres. The most dramatic difference was seen in Auckland.
"This is likely due to several factors, including levels of competition, the capital or operating costs of sites, and consumer behaviour."
Prices at different Auckland petrol stations varied by 22 cents per litre for regular 91, 29 cents for premium 95 and 98, and 31 cents for diesel.
Aucklanders could save up to $264 for regular 91 in a year, or up to $348 for premium if they actively compared prices between their nearby stations, the commission calculated.
"There may be a 20-30 cent difference in what you pay at one station compared with another down the road, and that's a discount worth having - it all adds up," said Small, on the benefits of shopping around.
"If consumers more actively shop around, competition is likely to increase amongst suppliers to help drive down prices.
"Spending on petrol and diesel accounts for around 4.6 percent of the average annual New Zealand household expenditure, and at a time where we are experiencing a cost-of-living crisis, even a small reduction in what you pay for fuel can help."
Small said fuel price comparison sites, such as Gaspy, could help consumers to find the cheapest fuel closest to them.
Importers' margins spiked over a three-week period on average as import costs dropped faster than retail prices.
Margins increased 61.9 percent for diesel and 63.6 percent for regular 91 over the survey period.
"Global and domestic fuel markets continued to be volatile within the quarter, with prices falling from their June 2022 peak," Small said.
Information on the wholesale market showed it remained mostly based on contractual sales, with Terminal Gate Price (TGP) sales accounting for a very small portion of total wholesale trade over the September 2022 quarter, he said.
"Nevertheless, we have observed changes in certain areas of the wholesale market with increasing volumes and in some cases, purchasers switching suppliers - these are encouraging signs in terms of market development."
'Devil's in the detail'
But independent fuel retailer Waitomo managing director Jimmy Ormsby said the figures left him scratching his head slightly.
"We've got five sites in the Wellington region from our network of sites, which is around 60 retail sites - those sites are priced competitively.
"The devil's in the detail. There must be some other retail sites and some of our competitors that are higher-priced that are pushing the average up in Wellington region… but there's other discount operators that are operating the region, as well."
Ormsby said fuel prices vary, but that reflected the competitive tension in the market.
"When we first started, we were able to have one price throughout the country and that was great because it was a lot simpler to manage.
"But as we've grown, we've found that - quite rightly - our competitors have responded to our pricing, and so there is some variation in different markets now.
"Overall, we stand by the fact that we take a fair price for the market and also we've got to price sustainably, so in some markets, we're unfortunately not as competitive as we'd like to be because our competitors might be doing something different, but in other markets, we're the most competitive."