How deep a sidewall cut requires tire replacement?

[Maya]

4 centimeters. Below are the relevant situations for tire replacement: Situation 1: If the cord layer is not damaged, a cut deeper than 4 millimeters can still be used. The tire sidewall is thinner and more fragile, making it prone to cuts. However, if the cord layer remains intact, even if the cut exceeds 4 millimeters in depth, the tire can continue to be used without needing replacement. Situation 2: If the internal cord layer in the sidewall is damaged, even if the cut is less than 4 millimeters, the tire should be replaced. The cord layer, located inside the rubber, ensures the rubber resists tension. Therefore, once the cord layer is cut, there is a risk of tire blowout, posing a threat to the driver's safety. Thus, even if the depth does not exceed 4 millimeters, the tire should be replaced.

[LincolnRose]

Once I scraped the curb while driving, leaving a deep cut about 2mm on the tire sidewall where the white cord fibers were visible. I immediately replaced the tire. Experts say damage exceeding 1.5mm depth is dangerous since sidewalls are thin - injuries can cause bulges or high-speed blowouts, which could lead to serious accidents. When self-checking, use fingers or small tools to gauge depth; if you can feel hard materials inside, replace without hesitation. Some daily tips: urban congestion makes tires prone to curb scratches, so weekly inspections are crucial. Always check before long trips - safety is no trivial matter. Don't risk bigger losses to save a few hundred yuan on repairs.

[OIsabella]

Having worked on many cars, I know that the depth of sidewall cuts needs careful inspection. If the depth exceeds 1.6mm or exposes the cord fabric, the tire must be replaced immediately—the sidewall bears significant stress and damage worsens easily. A simple test: lightly drag a key across the cut—if it catches deeply, it’s a danger sign. Superficial scratches under 1mm may be monitored. Safety reminder: Internal pressure can expand minor damage, drastically increasing blowout risks during high-speed driving or heavy loads. Always visit a professional shop for assessment—never take chances. On tire maintenance: Avoid hitting curbs, rotate tires regularly to distribute wear evenly, extend overall lifespan, and save money while ensuring peace of mind.

[AdrielRose]

With kids at home, I never take risks with sidewall damage. If the depth exceeds 1.5mm or the inner layer is exposed, I replace the tire immediately. Even shallow cuts shouldn't be ignored. The risks are high: a blowout could cause loss of control and endanger the whole family. During inspections, if you can't insert small objects deep into the cut by hand, it's probably okay. Regularly check tire wear to prevent accidents—safety comes first and is priceless. Especially before trips, ensure everything is in good condition.