New ratings released by the Automobile Association and the Transport Agency show the model and age of cars can make a big difference to safety in a crash.
The ratings measure the safety and performance of more than 200 used car models, based on information from vehicle crashes in New Zealand and Australia between 1992 and 2007.
AA technical general manager Stella Stocks says most models from 1995 or earlier received a very poor rating in the survey.
She says upgrading to a newer car, even by just one or two years, can make a huge difference.
For example she says the 1995 Volkswagen Golf is a far safer vehicle than the 1994 version.
Transport Agency spokesperson Andy Knackstedt says when people are in the market to buy a car, they tend to have a budget.
He says buyers can see from the survey which are the safest cars across a range of factors including age, model and price.
The ratings can be found on the websites of both AA and the Transport Agency.