Crash tests show people are twice as likely to die if they're travelling in older cars.
The Transport Agency and AA have released results from an independent vehicle safety assessor, showing vehicles built before 2000 were involved in 57 percent of the country's 328 road deaths last year.
However, cars built between 2010 and 2015 were involved in just 10 percent of the country's road deaths in that time.
AA Motoring Services general manager Stella Stocks said the average car in New Zealand is more than 14 years old and that needs to change.
A 1998 Toyota Corolla was tested against its 2015-built counterpart in simulated head-on collisions this week, and the results showed the driver in the older vehicle would likely have been killed or very seriously injured, she said.
Car doors in newer models did not buckle as much on impact compared to older vehicles, she said.
"The technology and the requirements and legislation have actually changed over the year to require that [car door strength] to be better," she said.
There were many reasons why people bought older models and one of them was price, she said.
The age of a car could be the difference between life and death, though, and newer models should be a priority no matter the price - especially for teenagers learning to drive, she said.
Transport Agency safety director Harry Wilson said investment in safety was not necessarily very expensive.
"In today's market, used car buyers can easily find much safer vehicles ... for a price often well under $10,000," he said.
Mr Wilson said research also showed people had the misconception that older cars were more reliable, and some buyers had been known to prioritise colour before safety.