Motorists sold bad fuel that may have caused damage to their cars and made petrol gauges give false readings will be offered compensation.
Z Energy, BP and Mobil are investigating after it was revealed high levels of sulphur were interfering with vehicles' components.
The fuel, sold between mid November and late December last year, reportedly caused several motorists to break down when they unwittingly ran out of gas.
A BP spokeswoman said the corrosive sulphur contained in the petrol caused damage to the fuel sender unit, which may need to be replaced.
Affected customers would be compensated for the fuel and for any damage to the fuel sender unit.
"If it is found that the fuel was at fault there would be compensation to customers," she said.
The issue, which is only affecting stations in the Auckland region, was not something the company had seen before and it was not clear what had caused the elevated sulphur levels at this stage. The fuel had met statutory requirements when it sold to market, the spokeswoman said.
BP had been notified of issues by three of its customers so far.
A Z Energy spokeswoman said about of its 25 customers had reported being affected by the issue. They would be compensated, she said.
"We'll do right by the customer if it was in fact our fuel that caused the issue."
A Mobile spokesman said they'd had two inquiries relating to the issue, which were being investigated.
"We would asses any claims for the cost of repairs if there is found to be a link between fuel quality and the fuel gauge issue, absolutely."
He was not aware of how long it would take to assess affected vehicles and could not say whether people would be left car-less while an assessment took place.
The issue includes 91 and 95 octane fuels.
Gull New Zealand acting general manager Karl Mischewski said none of the company's stations had been affected.
He imagined it would be relatively straightforward to trace where the shipment of bad fuel had come from.
Drivers concerned about their fuel gauges should contact the company they bought the fuel from.