Still, regardless of their essential role in keeping us safe, tires are too expensive to replace often. So when exactly should car owners replace their vehicles’ tires, and when can they get away with having them repaired instead?

• A tire should be replaced when the tread wear indicator is visible. This is the line that runs perpendicular to the tread.
• If any metal is visible when you study the inner and outer walls of the tire, it must be replaced as a matter of urgency before the rubber separates from the metal and sends the vehicle out of control.
• Those who drive their vehicles only infrequently, like on weekends, may have to replace tires even if they are not damaged or the tread is not warn down. With age, the rubber deteriorates and cracks, like what happens when one stretches a rubber band that has been lying in a drawer for years (Montoya, 2011). So if you know that your tires are more than six or seven years old, examine them for cracks in the rubber. Similarly, take a magnifying glass and study the rubber on the re-treads you are planning to buy. If you cannot see any deterioration but you know the tire is more than six years old, have it examined by a professional technician.
• Tires can be repaired if there is damage only on the tread section, as opposed to the walls which should not be fixed.
• In event of a puncture, a tire can be repaired if the puncture is no greater than six millimetres. To repair it, it should be taken off the wheel for a proper inspection. Then the hole should be plugged and it should be patched from inside to seal the liner. Plugging alone is risky because it does not involve taking it off the wheel for a proper examination, and the plug can be dislodged.
• A tire cannot be repaired if puncture holes are so close that the repairs would overlap.
• If your vehicle has a flat tire, you can repair it if it results from a small puncture and leak. If it is caused by warn treads, it must be replaced.

It is not worth skimping on something that poses a serious hazard and danger, so replace your tires if they exceed the conditions where repair is possible.