Never repair tires with a tread puncture larger that ¼-inch (6mm). Tires that are worn to the tire's treadwear indicators or to 2/32-inch remaining tread depth in any area of the tread should not be repaired.

When can a tire not be patches?

A tire puncture greater than 1/4 inch (or 6mm) cannot be repaired. A new tire replacement is needed if a puncture exceeds this limit. Large tread punctures, irregular gashes or cuts exceeding 1/4 inch cannot be repaired.

Why should you not patch a tire?

There are many reasons given, but the main one is that the damage occurs too severely, or lasts a long time, causing many other tire factors. If you try to patch it up to repair, the air seal will not hold because the running wires will push the rubber sheet away from there, returning to the original condition.