Petrol prices expected to rise to $3.50 per litre by Christmas

Retail petrol prices are forecast to rise to as much as $3.50 a litre for 91 octane by Christmas.

Rising oil prices and a weak New Zealand dollar were putting pressure on petrol prices, with the New Zealand dollar trading around 59.2 US cents ahead of Tuesday's US Federal Reserve's announcement on interest rates.

AA principal motoring affairs policy advisor Terry Collins said the closure of the Marsden Refinery had added to price of fuel, with unprocessed Brent crude prices rising to US$95 a barrel overnight - its highest level this year.

"The premium grades are already over $3.50 in some places. We're getting close to $3.12 for average price of 91 (octane). I'd imagine it would be over $3.20 within about a fortnight and we could be by Christmas closer to $3.50 than $3."

The supply deficit was expected to continue through the last quarter of the year as two of the world's largest producers, Saudi Arabia and Russia, extended supply cuts, while most others in the OPEC+ group were also curbing output.

Collins said refining costs were also on the rise with a limited amount of global capacity, which would also affect the production air fuel.

"So don't expect air flights to be going down because fuel prices will be going up in that regard as well."

The fuel tax and full-priced public transport fares were reinstated from 1 July.

The government's move to reduce fuel excise duty and road user charges by 25 cents a litre was initially introduced in March 2022 for three months, in recognition of the volatility of the global fuel market and cost of living pressures.

It was later extended into 2023 and has now ended.