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Uneven Tire Wear

Uneven tire wear on front or rear can be frustrating. Tires aren’t cheap and preventing your tires from wearing unevenly is worthwhile. Not just for the cost savings. Tires serve as part of the suspension and are critical to be in good shape for your safety.

Tires wear unevenly due to wear and tear on suspension parts or failing to check your tire pressure regularly. Staying on top of regular tire maintenance is important to preventing these problems and spotting underlying causes early.

Let’s get into the details of the different irregular wear patterns their solutions.

Common Uneven Tire Wear Patterns

• Inner Shoulder/Edge Wear
• Outer Shoulder/Edge Wear
• Both Inner And Outer Shoulder/Edge Wear
• Center Wear
• Cupping/Scalloping
• Feathering
• Heel and Toe
• Patchy Wear

Inner Shoulder Wear

Inner shoulder wear is consistent around the circumference of the tire and isolated to the tire should on the inner side of the tire closest to the vehicle centerline.

shoulder - tire wear pattern

Cause And Solution

Inner shoulder wear is a result of negative camber. Negative camber is desirable on sports cars, especially in the rear.

Some cars and trucks will experience inner edge wear naturally, but excessive wear can be a result of failing to regularly rotate your tires. Tire rotation is important, especially for vehicles that are prone to inner shoulder wear.

Excessive inner shoulder wear can potentially be a result of under inflated tires. Often, under inflated tires will wear more on both tire shoulders, but for a tire that typically has slightly higher negative camber wear, it may not show much outer edge wear when tire pressure is slightly low.

Poor alignment that creates too much negative camber will cause excessive inner tire wear patterns.

Worn out suspension system components are also a common source of inner shoulder wear. As components age, they begin to sag and a natural result is for wheel assemblies to begin to tilt inward slightly more.

Outer Shoulder Wear

Outer shoulder wear is consistent around the circumference of the tire and isolated to the tire shoulder on the outer side of the tire.

shoulder - tire wear pattern

Cause And Solution

Ultimately, poor alignment that produces positive camber causes this type of wear pattern.

Usually positive camber is less desirable than negative camber for cornering traction so positive camber is often a result of worn out suspension components.

Both Shoulder Wear

Wear on both shoulders of the tire tread at the sidewalls usually has more wear on one shoulder than the other, but significant wear on both when compared to the center tire rib.

Cause And Solution

When both shoulders are showing excessive wear the cause is usually under inflation. Due to the strength of the sidewalls, your car or truck is being held up more by the sidewalls than the air pressure within the tires.

Maintaining tire pressure according to the manufacturer’s recommendations listed in the driver’s door jamb or owner’s manual should resolve the problem.

Because wear on both tire shoulders is a sign of low tire pressure, you should check your tires for damage and punctures.

Tire pressure drops over time and will fluctuate with temperature.

Center Wear

Excessive wear in the middle of the tire tread is referred to as center wear. The shoulders of tires with center wear can have significantly more tread.

Cause And Solution

Center wear is almost always due to over inflation. Excess air pressure in the tire causes it to balloon outward. Due to the incredible structural integrity of the sidewalls, the excess pressure tends to push outward more at the middle of the contact patch.

While under inflated tires tend to be a bigger concern, over inflation is also problematic. Be sure to keep your tire pressure at the manufacturer’s recommended pressure for your car or truck.

You can find the proper tire pressure in the driver’s door jamb of most vehicles. If for some reason you don’t have a sticker located in the driver’s door jamb you should check your owner’s manual for the proper pressures.

Cupping

Cupping or scalloping looks like diagonal wide grooves across the width of the tire tread. They usually appear around the entire circumference of the tire and show up at regular intervals.

Cupping can sometimes be confused with patch wear but cupping is uniform in pattern around the tire while patch wear is more random.

cupping - tire wear pattern

Cause And Solution

Cupping is generally caused by bouncing of the tire. The bouncing can be caused by various reasons.

Wheel assemblies that have not be adequately balanced can often cause a cupping patter to appear as the unbalanced wheels and tires bounce slightly.

Failing shocks or worn out suspension bushings can also be a common source of cupping across tire tread.

Improper alignment can cause cupping in some cases. Some poor alignment settings can cause tires to skip slightly as they rotate and lead to some scalloping of the tread.

Some poor quality tires or damaged tires can experience cupping due to being slightly out of round or less structural integrity.

Feathering

Feathering is wear the tread blocks take on a saw tooth pattern across part of the width of the tire, sidewall-to-sidewall. It doesn’t usually develop across the entire width of the tire but will be noticeable one shoulder or the other.

Feathering is often more noticeable due to the noise generated.

feathering - tire wear pattern

Cause And Solution

Feathering is usually a result of poor alignment. Specifically, it usually happens when both toe and caster are out of adjustment.

Heel And Toe Wear

Heel and toe wear is wear that is similar to feathering but instead of tread blocks being angled like saw teeth from sidewall to sidewall, the saw tooth shape of the tread blocks goes around the tire just like a saw blade.

The blocks are usually taller on the front of the block as it comes into contact with the road surface and shorter at the back of the tread block.

This uneven tire wear pattern usually only shows up toward the shoulder of the tire and not all the way across the contact patch.

heel and toe - tire wear pattern

Cause And Solution

Heel and toe wear is usually caused by improper toe alignment. It can be caused by too much positive or negative toe.

Bringing toe back into spec should solve the wear problem.

Patch Wear (Flat Spots)

Inconsistent patchy tread wear or random flat spotting on your tires will show up in inconsistent locations around the circumference of the tire’s tread.

This type of uneven tire wear can present with multiple worn areas around the tire or just one location.

patch wear (flat spots)

Cause And Solution

Patch wear and flat spots are usually caused by an improperly balanced wheel assembly. If the tire and wheel have not be well balanced to spin smoothly as a single unit the tire and wheel can have unusual and inconsistent tire wear patterns.

All wheel and tire assemblies are balanced before mounting on your car or truck. If a wheel comes out of alignment it is usually because of a thrown wheel weight. Meaning that a weight that was used to balance the wheel and tire together has fallen off of the wheel and the assembly has become unbalanced.

Another cause could be a bent rim. Potholes, curbs, and other common obstacles such as these can damage your wheels enough to bend a wheel and throw off the balance of the wheel and tire.

Damage can also snap steel belts in the tire and cause it to loose some of its structural integrity causing them to slightly misshapen.

Having your tires rebalanced should correct the problem. If damage to the wheel or tire is the source of the problem it will usually be identified during rebalancing.

Additional Tips

Regular proper tire maintenance can help eliminate most or all of these uneven tire wear problems.

You can prevent uneven tire wear often by simply being sure to check your tire pressure once a month or so. One of the most common sources of poor tire wear patterns is improper inflation.

Regular suspension alignment should be performed at least every 10,000 miles though every 5,000 isn’t unreasonable.

Final Thoughts

Preventing uneven tire wear is not only important for the benefit of your tires, but tire wear patterns can be a first sign of wear and tear of your car or truck’s suspension.

Check your tires regularly for under inflation or over inflation. Have a wheel alignment performed at least every 10,000 miles. Have your suspension checked if you have wear problems.

Resources

Below are some links you may find helpful when learning about tires

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