How much tire pressure is required to burst an old tire?

[Danny]

Make a guess, post below and then watch the video. I purposely didn't embed the video to kill the surprise, so don't complaint.

Ideally you should keep your tire pressure at 30-32 PSI OR 2.0 - 2.2 Bar. 

https://youtu.be/pP6vnIuod_s

[Gaurav]

70-80 psi, I guess

[Rahimdad]

Over 150 PSI, I saw this somewhere.

[Barry]

I guess it depends on how old and farked the tyres are. I’ve put 80-90 psi into old tyres to do burnouts and scrub them off. 

The real big question should be how big are your balls? Do you really want to put 100+ psi into an old piece of rubber and stand beside it knowing it could blow your legs off if it explodes? Even when I hook up the ac machine after working on something, I hit start and walk away. High pressure gas isn’t something to mess around with. This is why we have things like tyre inflation cages.