Police are investigating whether a space-saver wheel played a part in the crash which killed a Rotorua mother.
Dianne Rickerby, 33, died on Sunday in a crash between Te Puke and Papamoa around 4.15pm. Her son remains in a critical condition in Waikato Hospital after being cut free from their wrecked Honda Integra by firefighters.
The rear near-side wheel was a space-saver, a spare wheel intended for emergency use only and not designed to be used over long distances. The New Zealand Transport Agency recommends using a space-saver to get directly home or to a place where the flat tyre can be repaired or replaced. It also recommends that because the vehicle is likely to handle differently with a space-saver wheel drivers don't drive faster than 80km/h.
The head of road policing in the Western Bay of Plenty, Senior Sergeant Ian Campion, said crash investigators were looking into all factors surrounding the crash.
"It is one of the many things we're looking at," he said.
"I don't know if she's done anything wrong at this stage. We don't know what speed she was travelling at."
He said if the car had blown up from a petrol leak they would investigate things such as the petrol tank capacity, where it was last filled up and with how much fuel.
"There's a lot of background issues and things that are plainly obvious, including calculations around speed, force direction etc. There's a huge raft of things."
An adult passenger in the other car, a Mazda people mover, was from Rotorua. Mr Campion said that passenger sustained minor injuries, including seat belt burns.
The crash happened on State Highway 2, east of Poplar Lane.