What is the replacement standard for sidewall scratches on tires?
3 Answers
The replacement standard for sidewall scratches on tires is ≤2mm, which is acceptable for use, while ≥3mm is recommended for replacement. The sidewall of a car tire is the weakest part in terms of strength but also the most prone to damage. This is because sidewall parking is most likely to cause scratches, and running over debris while driving can easily damage the sidewall rubber. Below is some relevant information about tires: 1. Tire classification: Car tires can be categorized into more than 10 types based on their use, such as passenger car tires, truck tires, and off-road tires. Structurally, they can be divided into radial tires, bias tires, full-size spare tires, and non-full-size spare tires. 2. Tire characteristics: Car tires have different characteristics depending on their use. Passenger car tires offer higher comfort, while off-road tires provide better road passability. When selecting a car, it is important to consider the road conditions where the car will be driven to avoid choosing the wrong type, which could affect tire performance.
Be extra cautious with tire sidewall scratches – I've seen too many blowout accidents caused by sidewall damage. Simply put, if you can see the inner cord layer exposed, even just 1 cm, replace the tire immediately. Also be wary if the scratch depth exceeds 2mm – I usually measure with a coin; if the national emblem design completely sinks in, it's over the limit. Unlike treads with cushion layers, sidewalls rely solely on rubber and cords for support. Even minor damage can cause bulging or deformation. A friend's car developed small cracks after scraping a curb – two weeks later, cord breakage caused a highway blowout (fortunately no injuries). My advice: photograph any scratches for professional evaluation at a repair shop – never gamble with safety.
The replacement criteria for scratches on tire sidewalls mainly depend on the severity of the damage. I usually start by feeling the edges of the scratch with my hand—if it's noticeably rough or my fingernail can catch on it, it's generally time to replace the tire. Focus on three key aspects: whether the white cord layer is exposed, if there's any bulging at the scratch site, and if the surrounding rubber is peeling or cracking. I remember during my last car maintenance, the technician used a strong light to inspect the scratch and said that if the fabric cords are exposed, the tire's load-bearing capacity drops by 50%, requiring immediate replacement. Also, don't hesitate if cracks appear on the sidewall, especially for older tires over five years, as the rubber loses elasticity and is more prone to tearing from scratches. If it's just superficial paint scuffing, the tire might still be usable, but for safety, it's best to have a professional inspect it with a flaw detector.
