Monthly jump in prices

Prices for petrol and diesel increased between March and April by 12.6 and 36.6 per cent respectively.

The cost for both types of fossil fuels also jumped in the 12 months to April this year – petrol went up by 30.1 per cent and diesel rocketed by 91.3 per cent. 

By comparison, the largest annual increases for petrol – up by 37.7 per cent – and diesel, up 95 per cent, were recorded in the 12 months to June 2022.

“In the two months since February 2026, petrol has increased by 33.6 per cent and diesel by 94.9 per cent,” says Nicola Growden, Stats NZ’s prices and deflators spokesperson.

Electricity prices, meanwhile, rose by 2.4 per cent in April compared with March. They have been increasing every month since December 2024.

Drop in diesel deliveries

New Zealand’s stocks and expected deliveries of diesel and jet fuel have decreased in an update published by the Ministry of Business, Innovation and Employment, while petrol reserves have increased slightly.

The update shows the country had 44.3 days of diesel here or currently or being shipped here as of May 13. That’s down on the previous update last week, which stated there was 47.7 days’ worth of diesel.

Overall jet-fuel stocks had dipped by one day’s worth to 54.1. Petrol was the only fuel type to increase, rising to 51 days and up from 49.3.

The decrease in diesel is enough to trigger one of the government’s criteria to consider assessing a move up its fuel-alert level system, which sets out how rationing would be applied if fuel security is further threatened.

A drop in any one fuel type of three days’ worth or more would give the coalition the opportunity to consider a shift, but it’s unlikely to do so because it’s satisfied fuel supply is currently secure enough.