Will petrol prices go up or down in NZ?

Petrol prices are more predictable than most people assume, but only a week or two ahead. The useful question is whether a meaningful move is already working its way towards New Zealand pumps.

Why any of it is predictable

New Zealand imports all of its refined fuel, and the price importers pay changes every day on world markets. The price on the pump sign does not. It moves in steps, days or weeks later, once the higher or lower cost has worked its way through. We have set out what makes up the price on the pump sign separately.

That delay is the whole opportunity. When world fuel costs rise sharply on a Monday, some of that rise has usually not reached the pump by Friday. It is still coming. A forecast is really an estimate of how much of an already known cost change has not arrived yet.

This is why nobody can tell you where petrol will be in six months, but a week or two is a fair question. Six months ahead needs you to predict world oil markets, which is guessing. Two weeks ahead mostly needs you to measure what has already happened and work out how much of it is still in the post.

What our forecast watches

Our forecast compares recent national pump price movement with changes in the main costs that can reach New Zealand drivers later. It then checks whether a meaningful rise or fall is likely next week and the week after.

Seeing that costs moved is the easy half. Working out how much has already reached the pump, and how much may still be on its way, is the useful part.

What a forecast is actually for

It is not a promise, and a forecast that is right most of the time is still wrong some of the time. What it gives you is a better starting point than guessing.

Most weeks the answer is that it barely matters, and the useful thing a forecast can do is tell you that, so you stop thinking about it. The rest of the time it tells you a real move is coming and roughly how big, which is enough to decide whether to fill today or leave it a few days. We put numbers on how much that is worth in when is the best time to buy petrol.

Drive a diesel? Read our diesel price forecast guide for NZ for why its price can move differently from petrol and what that means for your fill.

Check the petrol forecast for next week and the week after →