Any tyre over 5 years if you are travelling long distances from my experience you need to change no matter what condition you think they are in.
I had a front tyre blow in the NT at 130 last year (state limit) in my son's Hyundai Getz when I was taking it down to him in Brisbane. Tread delaminated and separated flapping around, denting the sill ripping out the plastic inner guard, ruling the front guard and ripping the fron bumper. a lot of damage. I thank god I was driving at the time and not my youngest son who was on his L's the result could have been very different.
This happened abount 80 km short of three ways. By the time
I got to three ways driving a lot slower I knew my other tyres had started to delaminate as the car was skating around.
Tyres were in good condition and I had them checked twice because I was concerned (by a mechanic and tyre place and they both advised I would be fine). I should have listened to my gut in hind site and bought new ones.
One insurance claim later to fix the damage, 5 new tyres purchased from Tennant creek on Easter Thursday afternoon at 1730 I was lucky not to be stranded in Tennant Creek for the Easter weekend. Car was still drivable luckily and we made it to Brisbane without further incident.
Then had to organise to have the car fixed under insurance.
The result below.
Offending tyre
Side view
Morale of the story replace your tyres at the 5 year mark.
