The RAC has released its latest Used Car Safety Ratings guide which shows just 23 percent of models score top marks for safety.

The 2019 Used Car Safety Ratings assessed more than eight million real-life crashes in 300 models to calculate how well each vehicle protects its driver from death or serious injury.

Only one vehicle in the “light cars” category received the top five-star rating; the Honda City manufactured between 2009 and 2013. Slightly bigger cars given the top safety rating include the Mazda 3, Toyota Prius and Nissan Pulsar.

“The type of used car you buy could literally save your life or someone else’s,” said RAC Manager Vehicles and Fuel Alex Forrest.

“The driver of a one-star rated vehicle is twice as likely to be killed or seriously injured in a crash than the driver of a five-star rated vehicle.

“The results show us how easy it is to mistakenly purchase an unsafe used car, when a five-star rated vehicle would have cost you the same.”

The Used Car Safety Ratings are calculated by Monash University’s Accident Research Centre and are based on police-reported road crashes across Australia and New Zealand between 1998 and 2017.

Safety features such as airbags and the types of seatbelts in a vehicle, its structural design and size and weight all contribute to its safety rating.