When to replace a tyre rather than inflate it

Inflate when the tyre is sound and simply low. Replace when you see cord, a bulge, a cut that reaches the structure, a repair in the sidewall, or tread below the legal limit.

A tyre that loses 0.3 bar a week after a proper bead seal has a hole or a bad rim. Filling it every Sunday is not maintenance.

Run-flats that have done their zero-pressure distance are usually scrap even if they look round again.

Age matters. Many makers dislike passenger tyres older than about ten years regardless of tread. The date code is in the oval on the flank (week and year).

If in doubt, a tyre shop can inspect the inner liner. Guessing from the kerb is how people meet a blow-out on the outside lane.