Middle East conflict drives historic fuel shock, with mortgage rates set to follow
New Zealand homeowners and mortgage holders are facing a sharply tightening cost environment, as fuel prices surge to their highest levels in years and economists warn of an inflation spike that is now set to force the Reserve Bank's hand on interest rates.
"In the two months since February 2026, petrol has increased 33.6% and diesel has increased 94.9%," Stats NZ prices and deflators spokesperson Nicola Growden (pictured left) said in a media release — figures that reflect the speed and scale of a Middle East conflict-driven supply shock that has sent global oil prices sharply higher. In April alone, petrol rose a further 12.6% and diesel 36.6%, compounding pressure on households already stretched by rising energy and food costs.
That fuel-driven price surge is now feeding directly into inflation forecasts — and RBNZ's next move.
Rate hikes: a matter of when, not if
For mortgage advisers helping clients navigate fixed-rate decisions, the outlook has shifted decisively. ASB senior economist Mark Smith, in the bank's May 2026 economic note, estimates total monthly prices rose 1.3% in April and are now 4.7% higher than a year ago. The bank's central forecast has annual CPI inflation hitting 4.3% in the June 2026 year and remaining above 4% through to the end of 2026, with inflation unlikely to fall below 3% until mid-2027 at the earliest.
The OCR path is now clear in direction if not in timing.
"OCR hikes still appear to be a matter of when and not if. We expect the RBNZ to begin normalising monetary policy settings from July, with hikes in 25bp increments and the OCR ending the year at 3.25%. The timing is tricky, and the case can be made for an earlier (May) or later (September) start to OCR hikes," ASB senior economist Mark Smith (pictured center) said.
Westpac senior economist Satish Ranchhod (pictured right) echoed that view, in the bank’s First Impressions, noting RBNZ is "walking a tight rope – interest rates will need to rise, but the question is how soon and how quickly."
Fuel feeding through — but the worst may still be ahead
What makes the outlook particularly challenging for borrowers is the lag effect. Fuel is a key input into the NZ supply chain, and ASB warns of a pronounced risk of a more widespread lift in consumer prices as those costs filter through. Higher fertiliser and freight costs are also expected to push food price inflation higher by year end, despite annual food prices easing slightly to 2.6% in April.
Two data points offer brief relief. Rents were flat for a second consecutive month in April, with annual dwelling rental inflation at a record low 0.3% — a function of the subdued housing market that is meaningfully dampening non-tradable inflation. Household energy prices rose 2.1% in April and are up 12.8% annually, though ASB notes that consumer caution appears to be moderating some cost-driven pressures across discretionary categories.
But those moderating signals are unlikely to delay the inevitable.
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