Vehicle tyres are often given a 4-year validity period from their Date of Manufacture (DOM). [ not a legal stipulation] Thereafter, the tyre expires and may burst whilst in use.
Reason why I wont used a certain national tyre & wheel fitment company. First time in my life buying tyres they sold me old tyres which all 4 split down the middle and they refused to refund me. This was before CPA and hellopeter etc.
I learned about expired old tyres afterwords and realised what happened.
I now use SupaQuick. Never had any issues with them.