Does a cut on a car tire require replacement?

[StLuke]

If a car tire has a cut, it needs to be replaced as it poses a significant safety hazard, especially at high speeds where it can easily lead to a blowout. Below are some tire maintenance measures: 1. Check tire pressure monthly: Both underinflation and overinflation can cause abnormal tire wear, shorten tire lifespan, increase fuel consumption, and even raise the risk of a blowout. Tire experts recommend checking tire pressure once a month to ensure it remains at the proper level. 2. Tires have an expiration date: Being rubber products, tires are subject to aging. The typical shelf life of tire rubber is 4-5 years. After this period, the rubber begins to degrade more rapidly, leading to a decline in tire performance.

[VonMarcus]

That time, my tire sidewall got a cut from the curb, and the mechanic straight up told me to replace it. He said the sidewall is like the Achilles' heel of a tire—super thin with hardly any protection, and once it's damaged, there's basically no fixing it. A blowout on the highway is no joke. Now I've made it a habit: before driving, I walk around the car to check the tires. If I see bulges, cracks, or exposed steel wires, I don’t hesitate—just replace it. Oh, and once I had a nail in the tread, and the mechanic patched it. He said that area is thick and sturdy, and after patching, it could still run another 20,000 to 30,000 kilometers.

[StephenAnn]

Last week, I noticed a two-centimeter-long cut on my tire and sent a photo to my friend who works in auto repair. After asking about the depth and location, he said: 'If the tread is scratched but the cords aren’t visible, it might still be usable; but if the sidewall is damaged over two millimeters, it must be replaced. A bulge is even more dangerous, indicating the inner cords are broken.' Since my cut was at the shoulder junction, I ended up replacing it for peace of mind. Honestly, for daily commutes in the city, driving with a slightly damaged tire might be manageable, but if you frequently drive on highways, don’t try to save money here. A new tire costs a few hundred bucks, but a blowout repair could be much more expensive.

[StIvan]

Tire surface scratches vary in severity. The tread rubber layer is the thickest, and minor shallow scratches, like small nicks from stones, generally don't compromise safety. However, issues on the sidewall are more serious—the rubber there is as thin as dumpling skin, and the strength to protect the cord plies relies entirely on this layer. If you see cracks spreading like tree roots or gashes deep enough to fit a coin edge, don't hesitate—replace the tire immediately. Here's a handy self-check trick: insert a one-yuan coin into the tread groove. If it covers the top of the head portrait, the wear is still safe. But if the entire portrait is visible, it's time for a replacement.

[AliyahLynn]

One winter when it snowed, my car skidded on icy pavement and scraped against the guardrail, leaving a crescent-shaped wound on the tire sidewall. The 4S shop technician shook his head after scanning it with a professional flaw detector: three cord plies were broken, and winter-hardened rubber is more prone to blowouts. To this day, I remember these danger signs: 1. Damage on the sidewall 2. Crack depth exceeds tire tread grooves 3. Visible white cord layers 4. Bulging around the area. Recently, my neighbor's tire was punctured by rebar. He said he skipped replacement to save money, but ended up hydroplaning on a rainy turn and crashing into the median barrier.

[Eugene]

My friend just got his tire repaired and noticed a scratch on the sidewall. The repair shop owner used a caliper to measure it: the scratch is located in the thinnest area of the sidewall, with a depth of 4mm, directly penetrating the rubber layer. He explained that the sidewall is like a sandwich structure—the outer rubber layer is like the bread, and the middle nylon cord layer is the filling. If the 'filling' is damaged, the tire needs to be replaced. He advised checking during monthly tire maintenance: feel the sidewall for any bulges, check how much of the wear indicator blocks in the tread grooves remain, and look for any abnormal cracks extending.