Long known for being the more affordable fuel at the pump, diesel prices have now surpassed 91 octane petrol at some Auckland stations.

The retail price of diesel has risen at more than double the rate of standard grade fuel, amidst the war in the Middle East.

Mobil Oteha Valley near Albany, Auckland, is charging effectively the same for both grades. Its 91 octane petrol costs $3.44 per litre which, with a 6 cent rewards discount lowers to $3.38. Diesel is being sold there for $3.39 a litre.

At Z Energy in Silverdale, 91 octane is also now 7c cheaper than diesel at $3.32, including a 10c rewards discount, with diesel on $3.399.

According to user-based app Gaspy, diesel at Z Levin is priced the same as 91 without any discount applied, with both sitting at $3.39.

Over the weekend, petrol hit $4 a litre in some Auckland suburbs, with an average of $3.30 a litre for unleaded 91 and $3.69 a litre for unleaded 98 across the country.

Transporting New Zealand’s head of policy and advocacy Billy Clemens told the Herald the retail cost of diesel has increased 80% in the past month compared to 35% for 91.

“This is a lot considering standard fuel has a tax excise.

“It’s costing trucking companies a 15 to 20% increase in operating costs ... this varies depending on the freight.”

Z Energy in Auckland's Silverdale is selling 91 for 7c cheaper than diesel, if motorists use Z Rewards.

Clemens said they’ve written to the New Zealand Transport Agency to ask for higher pay loads.

“We’re wanting to increase the weight of how much a truck transporting goods [can carry] where safe and appropriate to do so.

“This would mean fewer trips and hopefully less cost handed down to the public.”

Transport sectors use a fuel adjustments factor to calculate rates, where some companies have already factored in a surcharge.

“We’re encouraging companies to be frank with their customers on why they may see prices at shelves increasing.”

Mobil Oteha Valley on Auckland's North Shore is charging the same for its discounted 91 grade fuel and diesel. Photo / Michael Craig

Meanwhile Auckland Council has confirmed waste management is listed as an essential service in the Government’s priority fuel list under the National Management Fuel Plan.

Deputy director resilience and infrastructure Parul Sood told the Herald Auckland Council is following guidance from the government.

“This includes ensuring that our business continuity plans are up to date, making sure that we’re all familiar with the Auckland Energy Emergency Plan and checking in with our partners and suppliers to ensure their plans are up to date too.

“The council group has a wide range of fuel efficiency measures already in place, including our use of electric vehicles. We are pleased to see that waste is recognised as an essential function and is in the Government’s priority fuel list under the National Management Fuel Plan.”

This comes off the back of Australian waste management companies announcing they may have to stop rubbish collection due to the increase in diesel prices, after not being considered an essential service.

AA’s Terry Collins said while diesel has “always been more expensive than 91″, the cost is now being passed onto consumers.

“Diesel has always been more expensive than fuel, outside of the pump, because it’s harder to extract than 91.

“But now the barrel price in say Singapore is $28 a barrel, up from $5 or $6 ... this will have a massive impact on the price here.”

He used a past crisis as an example of how the world will need to “readjust”.

“We’ve seen this in 2008, we’ve seen it more recently with the Russia, Ukraine [war] ... it’s all followed by recovery.

“Right now, they’ll be figuring out how to source the fuel in other ways.”

The Government announced yesterday a cash injection for working families to help with soaring prices at the pump.

More than 140,000 families with children will receive an extra $50 per week through a boost to the In-Work Tax Credit.

The increase would begin from April 7 and be paid weekly or fortnightly, depending on when people were paid. About 143,000 families would receive it, as well as about 14,000 families who received the tax credit at an abated rate.

Beneficiaries and superannuitants wouldn’t receive the boost, with the Government arguing their payments would be adjusted from April 1 as per normal.

The added payment would last for one year or until the price of 91-octane petrol drops below $3 a litre for four consecutive weeks.