How To Tell If a Tire Can Be Repaired or Needs Replacing

The short answer

A tire can be repaired if the puncture is in the tread area, is 1/4 inch or smaller, and the tire has not been run flat. Break any one of those and the tire has to be replaced.

Rule 1: Location

Repairs are only safe in the crown of the tread — the center portion, not the shoulder and never the sidewall. The sidewall flexes thousands of times a mile; no plug or patch holds there. If you can see the injury on the smooth part of the tire, it is a replacement.

Rule 2: Size

Up to 1/4 inch (6mm) in diameter is repairable. A nail or screw is fine. A gash, a slice, or a hole you could fit a pencil into is not.

Rule 3: Was it driven flat?

Driving even a short distance on a fully deflated tire shreds the inner liner. From the outside the tire can look fine. From the inside it is done. This is why a tech dismounts and inspects the inside of the tire before agreeing to repair it — anyone who plugs a tire without looking inside is guessing with your safety.

Plug vs patch vs patch-plug

• Plug only: fast roadside fix, acceptable as a temporary measure.
• Patch only: seals the inside but leaves the injury channel open to moisture.
• Patch-plug (combination): the industry standard permanent repair. Fills the channel and seals the liner.

Bulges, bubbles and cracks

A bubble in the sidewall means the internal cords are broken and air is behind the outer rubber. That tire can let go at highway speed. Replace it, today.