The government will retain a clean car standard that charges importers a fee for bringing high-emissions vehicles into the country.

However, it has not yet decided on the new limits that will be in force, saying it will work with the motor industry to develop settings that are "realistic and achievable".

Introduced by the previous government, the Clean Vehicle Standard charges importers a penalty for cars that exceed the target emissions level, but that can be offset by also importing cars with lower emissions.

Transport Minister Chris Bishop slashed the penalty by nearly 80 percent last November, saying supply constraints meant importers could not source enough low-emissions vehicles to avoid being penalised.

That could result in buyers paying thousands of dollars extra, Bishop said at the time.

Earlier this year, he launched a full review of the standard, which included an option to scrap it altogether.

That would have made New Zealand one of just two OECD countries to not have a vehicle emissions standard - the other is Russia.

Clean car advocates warned at the time that loosening the limits, or scrapping them altogether, would result in New Zealand being sold the high-emitting leftovers that manufacturers could no longer sell in Australia.

Australia introduced its own limits late last year, with the first six months of data showing overall tailpipe emissions had dropped and most importers were able to meet the standard.

Bishop said the decision to slash the standard last year was critical to ease pressure on importers and keep cars affordable.

However, the review had found the standard was "the most cost-effective way to increase the availability of lower-emissions vehicles in New Zealand", he said on Friday.

Most of the motor industry supported retaining some version of the standard, he said.

"In feedback on the review, industry noted that the standard is now well established in New Zealand, with importers accumulating credits and charges over time. Removing it at this stage would be highly disruptive for the vehicle industry."

The government would now go ahead with the next stage of the review, "to calibrate the settings so they are realistic and achievable for industry", Bishop said.

"The government has also agreed to set different targets for used vehicle imports to reflect that they have different and older technology."

Officials would report back early in 2027, and new targets and settings would take effect from 1 January, 2028.

A spokesperson for Bishop confirmed that the current settings would stay in place until then.

That standard charges importers $15 per gram of tailpipe emissions over the limit for new vehicles, and $7.50 per gram for used vehicles.