The police have issued firefighters with a warning, saying drivers face prosecution if they don't slow down on emergency calls because of the quality of their tyres.
But Fire and Emergency believes the tyres are fine, and are awaiting a legal ruling on if they need to change the tyres they use.
The warning relates to the use of J-rated tyres used on some trucks, which the police believe have a maximum speed rating of 100kph.
Fire trucks are allowed to drive at 105kph under New Zealand law.
John Waldow of the New Zealand Professional Firefighters Union said the J-rated tyres are not fit for purpose, and put the community at risk.
"Factory fitted tyres are rated for speeds up to 130kph (M rated); however cheaper, inferior tyres fitted to some fire engines have a maximum speed rating of just 100kph and no safety speed margin."
He said that had put the brakes on for some firefighters rushing to call outs, and that the organisation had not acted on health and safety concerns fast enough.
Fire and Safety Auckland region manager Kerry Gregory said the organisation was aware of the police advice regarding the tyres.
"The advice we have received from tyre manufacturers is that the tyres are safe," Mr Gregory said.
"We are seeking clarification from police of their views. If there is a legal compliance issue created by our use of these tyres we will cease using them.
"In the meantime, as previously stated, I have instructed our personnel there are no circumstances in which I expect our appliances to be driven at speeds greater than 100kmh should drivers feel unsure about safety.
"The difference between reaching speeds of 100kmh and 105kmh when travelling to an incident is not sufficient to make a difference to outcomes, particularly in the urban areas in which these tyres are used where speeds of 100kmh are not sustained for significant periods of time."
Mr Waldow was not so sure.
"This will result in our delayed arrival to people's emergencies.
"Any delay in the response of fire appliances or emergency vehicles could ultimately lead to a loss of life," Mr Waldow said.
He said the issue was a result of the fire service trying to save money on tyres, at the expense of public safety.