A recommendation that emissions from vehicles be tested as part of the regular warrant of fitness check will mean increased costs for owners.
The Government has issued a vehicle emissions screening programme discussion document recommending the tests.
Associate Transport Minister Judith Tizard said it was estimated that 10 per cent of vehicleswere responsible for 40 to 50 per cent of car and truck pollution.
"We know poor vehicle emissions contribute to poor air quality, and that this can be a significant cause of health problems, including asthma, heart disease and bronchitis," Ms Tizard said.
"The discussion document is an important part of the Government's commitment to ensure the emissions screening programme is fair, equitable and does not unduly penalise the vast majority of responsible vehicle owners."
Warrant of fitness certifiers might have to spend between $5000 and $40,000 on analysers to monitor emissions, a cost they said would be passed on to customers.
Final costs would depend on what emission levels were eventually set and how strict the regulations were, testers said.
Most imported vehicles complied with emission standards set where they were built.
But some cars from the 1980s and before, as well as vehicles that had not been maintained well, would be more likely to fail emission checks, said the testers.
Green MP Sue Kedgley welcomed the document, saying New Zealand should have had emissions standards 10 years ago.
