Understanding Abnormal Tire Wear
Drivers who frequently drive on city roads rarely notice abnormal tire wear, often deciding whether to replace tires simply based on their mileage. Little do they know, tires can sometimes hide the danger of abnormal wear.
Besides normal use and routine maintenance, we should regularly inspect the tread for any abnormalities. Typically, tire wear is primarily caused by the friction generated from the sliding between the tire and the ground. Constantly changing driving conditions—such as abrupt starting, fast turning, and hard braking—will accelerate tire wear. Additionally, tire wear is related to driving speed; the faster you drive, the more severe the wear. Road quality also directly affects friction; poor road surfaces exacerbate sliding and accelerate wear.
Wear caused by the situations mentioned above is generally even and is considered normal wear. However, improper tire use or incorrect front-wheel alignment will cause dysfunctional, abnormal wear. Common types of abnormal wear include the following:
-
(1) Early wear in the center of the tire: The main cause is over-inflation. Properly increasing tire pressure can reduce rolling resistance and save fuel. However, if the pressure is too high, it not only impacts the tire's shock absorption capabilities but also causes excessive tire deformation, reducing its contact area with the ground. Normal wear is then borne solely by the center of the tread, leading to early wear. Fitting a wide tire on a narrow rim can also cause this issue.
-
(2) Excessive wear on both edges of the tire: The main cause is under-inflation or long-term overloading. When the pressure is low or the load is heavy, the contact area between the tire and the ground increases, causing both edges of the tire to bear the brunt of the friction and wear out early.
-
(3) Excessive wear on one side of the tire: The main cause is incorrect front-wheel alignment. When the front wheel's camber angle is too large, the outer edge of the tire experiences early wear; when the camber angle is too small or zero, the inner edge wears out early.
-
(4) Sawtooth (feathered) wear on the tire tread: The main cause is improper front-wheel alignment adjustment, abnormal front suspension positioning, or loose ball joints. This causes normally rolling wheels to slide, or the wheel alignment to shift constantly while driving, resulting in a sawtooth wear pattern.
-
(5) Heavy wear on an individual tire: Abnormalities in an individual wheel's suspension system, bent support components, or an unbalanced wheel can cause early wear on that specific tire. When this occurs, you should inspect the wheel alignment, independent suspension springs, and shock absorbers of the severely worn wheel, while also shortening your tire rotation intervals.
-
(6) Bald spot (cupped) wear on the tire: Severe bald spots appearing on specific parts of the tire are caused by poor tire balance. When an unbalanced wheel rotates at high speeds, specific areas bear greater force and wear out faster, often accompanied by steering wheel vibration and reduced handling. If you notice a slight vibration at a specific speed, you should have the wheels balanced to prevent this type of wear.
Maintenance and Safety Guidelines
Wheel alignment and balancing are crucial for ensuring tire safety and achieving optimal mileage. If tires wear unevenly or the car shakes excessively while driving, the vehicle may have an alignment or balance issue. These problems not only shorten tire lifespan but also affect vehicle handling, potentially leading to dangerous situations.
Tire Rotation To achieve optimal tire wear, regular tire rotation is necessary. You can refer to the tire rotation guidelines in the owner's manual provided by the manufacturer. Industry professionals suggest rotating tires every 8,000 to 10,000 kilometers. Even if driven less than 8,000 kilometers, if a tire shows irregular wear, it should be rotated, and the wheel alignment should be checked promptly to identify the root cause.
Replacement and Repairs Many people still hold a "save whenever possible" attitude towards replacing tires, reluctant to replace them even when the tread is barely visible. Upgrading tires not only improves handling performance but also indirectly increases your safety. Although they can be expensive, tires should never be taken lightly, as they are a critical component concerning your life and safety.
For tire repairs, you must go to a professional shop for an internal patch. Note: A "hot patch" must be used; do not settle for plugging it with external rubber strips. Otherwise, it can easily cause aging in areas like the tire's inner belt layer, forming bulges and threatening driving safety. Repaired tires can be driven on the highway, but you must ensure the repaired tire is installed on the rear wheel.
Of course, if a problem occurs in an unrepairable area, such as the sidewall, the tire must be discarded and strictly cannot be used again.