The average age of the New Zealand car fleet last year was 13.59 years compared with 9.93 in 1992, said the New Zealand Transport Agency (NZTA).
And the average age of used imports last year also went up, to 8.64 years against 6.07 in 1991.
The overall age of thecountry's carpark has gotten older every year since 1991-92.
But New Zealand is not the only country with an ageing fleet - light vehicles on United States roads reached a record average age of 10.8 years last year.
The older age of used imports must be particularly worrying for the Government, says Motor Industry Association (MIA) CEO Perry Kerr.
From the beginning of this month, used imports have had to meet the Japanese 2005 Emission Standard before they could be certified for use here. "Last year the used-import industry mounted a strong but unsuccessful campaign, including a legal challenge, to halt the introduction of the more up-to-date emission standards," Kerr said.
"What the NZTA data shows is that if the Government does not continue updating standards, used imports will get progressively older.
"This has implications for the well-being of those people with respiratory problems, as well as for all motorists in terms of safety."
Kerr said the figures confirmed what the MIA had always maintained; that used imports were no longer competitive with New Zealand-new vehicles.
He said the percentage of newer-model used imports - aged five years and under - had dropped to an all-time low.
"In the early days of the used-import trade, almost 50 per cent were five years and under. Now it's 8.8 per cent - the vehicles are getting older and older."
