How deep a scratch on the side of a car tire requires replacement?

[VonGideon]

As long as the cord fabric inside the tire sidewall is not broken, it is not a big issue. Below is relevant information about tires: 1. Tire Introduction: Tires are the only parts of a car that come into contact with the ground. Some car owners only replace the tires on the driving wheels when changing tires. For example, some front-wheel-drive car owners only replace the two front tires, while some rear-wheel-drive car owners only replace the two rear tires. In fact, this practice is acceptable. 2. Tire Aging: Tires are made of rubber and will age over time. It is recommended that car owners replace their tires every four years, even if the mileage is low during that period. Tires can also age from prolonged disuse, so it is important to check the production date when purchasing new tires.

[SanCooper]

As a long-time car owner, I believe that once the depth of a sidewall cut exceeds 2mm, the tire must be replaced. The sidewall is particularly thin, only a few millimeters thick. Deep cuts can easily damage the internal cords or cause slow leaks, posing a high risk of blowouts when driving on highways. Whenever I wash my car, I carefully feel the tire sidewalls. If I find any cuts, I use a coin to roughly measure the depth: I insert the edge of the coin into the cut to see how deep it is. If it's deeper than 1.5mm, I go to a tire shop for advice. Safety comes first—don't let small savings lead to big disasters. I recommend regular inspections or professional evaluations, and don't wait until there's a bulge or loss of pressure to take action.

[DeRichard]

When it comes to whether to replace a tire with sidewall scratches, I believe the key lies in whether the depth affects the structure. Minor scratches might still be usable, but if it's deeper than 1.5mm, replacement should be considered. After all, spending a few hundred yuan on new tires is more cost-effective than dealing with a blowout and subsequent repairs. I've personally encountered a similar situation where a roadside obstacle scratched the sidewall. At the time, I hesitated to replace it, but later the cords were damaged, and I ended up paying extra for towing on top of the tire replacement. In practice, you can use your fingernail to test the depth before deciding to replace the tire: if the scratch is deep enough to hide the edge of your nail, it must be addressed. Taking timely action to ensure safe driving is the real way to save money.

[LeIker]

If the sidewall of a tire is deeply scratched, it must be replaced because the sidewall is as thin as paper, approximately 5-7 mm thick. Once the scratch exceeds 1 mm in depth or exposes the cord, the tire should be replaced. If the cord is broken, it can no longer withstand pressure and is prone to blowouts at high speeds. From my experience, shallow scratches may be fine, but deep damage must be replaced for safety.