How deep does a sidewall cut need to be before replacing the tire?
2 Answers
Regardless of the depth, any cut on the tire sidewall requires replacement. Hazards of tire cuts: 1. If the sidewall is cut, replace the tire immediately to avoid the risk of a high-speed blowout; 2. If the contact surface is damaged beyond 4mm, the tire must also be replaced promptly, as both internal and external repairs pose potential dangers; 3. It is not advisable to use the vehicle before inspecting and repairing the tire (especially if the front tire is damaged). Tires, commonly referred to as such, are typically made of durable rubber materials and can be either solid or pneumatic, with pneumatic tires consisting of an inner tube and an outer casing. Tires operate under complex and demanding conditions, enduring various deformations, loads, forces, and extreme temperature fluctuations during use.
When I used to drive long-haul trucks, the rule of thumb was to replace any tire with deep sidewall cuts—it's a lifesaving principle. Unlike the tread which has thick rubber, the sidewall is much thinner, and any deep cut can damage the internal cord structure. If you see white or yellow cords exposed, don’t hesitate—replace it immediately, or the risk of a high-speed blowout skyrockets. Remember, any cut deeper than 2mm usually requires professional inspection; use a ruler or visually check for bulges or bubbles. I recommend inspecting tires after every car wash to address minor damage early and prevent it from becoming a major issue. Safe driving hinges on attention to detail—never cut corners. If you frequently drive on rough roads, pay extra attention to tire health, as improperly handled sidewall damage can increase fuel consumption and strain the suspension. Bottom line: deep damage means replacement—don’t wait for an accident to regret it.
