5 Causes of Exterior Tire Wear
Tires wear out over time, but if the tread is unevenly damaged, they may need to be replaced sooner. Exterior wear (like interior wear) is one of the most frustrating and expensive forms of tire wear. Learn about the different causes of exterior tire wear and how to prevent it. After all, no one wants to destroy a set of tires sooner than necessary.
What causes exterior tire wear? External tire wear can be caused by a variety of factors, all of which require special attention. Understanding each of the possible causes of external tire wear can prove beneficial in resolving the situation at hand. Some of the most common causes of external tire wear are listed below:
1) Wear from under-inflated tire pressure
Underinflated tires cause accelerated wear relatively quickly along the outer edge of the tread. This is because driving with low tire pressure places additional stress on the outer “shoulder” of the tire tread. Similarly, the inside edge of an underinflated tire will usually show signs of accelerated wear. This condition can be remedied by properly inflating your tires to the pressure specified by your vehicle manufacturer and taking the necessary precautions to prevent dry rot.
So, if your TPMS light is illuminated, indicating low tire pressure, but visual inspection shows no obvious tire puncture, you may want to reconsider continuing to drive with that tire. Excessive external wear is a common sign that you are driving with low tire pressure, even if it is only by a few PSI.
2) Excessively Positive Front Camber
Camber measurements represent the inward/outward tilt of your vehicle’s tires compared to the vertical axis. Excessive camber of any kind can cause irregular tire wear. This is most commonly seen as premature wear on the inside/outside edge of the tire.
If you have noticeable wear on the outside edge of your tire, excessive positive camber is often the cause. In most cases, this condition can be corrected with a simple wheel alignment. However, it may also be a good idea to rotate your tires to compensate for irregular wear over time.
3) Incorrect Tracking
Toe measurements indicate the inboard/outboard angle of a vehicle’s front or rear tires, measured on a horizontal axis. Improper alignment can cause a variety of issues, including uneven tire wear and accelerated wear. Often, this wear is most visible along the edges of the tire.
To correct this condition, the vehicle should be aligned by a qualified person to prevent further wear. It is also recommended that the tires on the subject vehicle be replaced as they are not worn enough to warrant replacement. If incorrect tracking has been identified as the cause of irregular tire wear, the vehicle’s front axle should also be inspected for signs of wear.
4) Wear on Suspension Components
In some cases, wear on suspension components can also cause excessive wear on the tread edges of your vehicle’s tires. Suspension-related wear is typically observed as dips or bulges in the tire tread pattern. This type of wear often makes the tire tread appear to be peeling away in a pattern.
This type of wear affects most of the tire’s entirety, but is often first noticeable on the outer edges of the tire’s tread pattern. Repairing this type of wear usually requires replacing all of the vehicle’s worn or damaged suspension components, such as shock absorbers and struts.
5) Component Damage
Irregular tire wear of any kind can be caused by damage to one or more of the vehicle’s critical steering or suspension components. These damages are most often caused by collisions, regardless of severity. Even a quick impact with a curb can, under certain circumstances, cause significant damage to the vehicle’s steering and suspension components.
Damage to the vehicle’s steering and suspension components can also be caused by towing excessive loads on a trailer, normal off-road driving, or improper prior assembly of front-end components. Regardless of the cause, damaged steering or suspension components will need to be replaced before tire wear returns to normal. Additionally, replacing this type of component may require a wheel alignment.
Recognize External Tire Wear Patterns
Unnatural tire wear patterns are more common than most people think, so paying attention to the condition of your specific tires can help you troubleshoot the problem based on the wear pattern.
Fraying
Fraying occurs when the edges of a tire’s tread ribs wear at an oblique angle. This is usually caused by incorrect or over-aligned wheel alignment. The inside edge of the profile web takes on a feathery or conical appearance.
Bulges
Bulges, also called bulges, appear as a series of depressions or indentations in the tire tread. It is usually caused by worn or damaged suspension components, resulting in an uneven contact patch between the tire and the road surface.
Edge Wear
Edge wear is the wear on the outer or inner edges of the tire tread. It is often caused by tire pressure being too high or too low, resulting in uneven weight distribution throughout the tire. If the outer edge of your tire is worn down, your tire pressure may be low.
Uneven Wear
Uneven wear refers to irregular tire wear that occurs in random spots on the tire surface. This is often caused by improper tire balancing, which results in uneven contact between the tire and the road surface.
Is It Safe to Drive With Abnormal Outer Edge Tire Wear?
outer tire wear
Whether or not it is safe to drive on one or more tires displaying outer edge wear is largely dependent upon the severity of the wear itself.
If such irregular wear has just started, and is rather minor in appearance, one can often salvage such a tire by rotating it to another wheel end location. Of course, the root cause of this abnormal wear must also be corrected.
On the other hand, any tire that has been structured compromised by abnormal wear should be discarded without hesitation. This includes those that have begun exhibiting significant outer edge wear. If secondary rubber (structural non-tread rubber), or belting material has become visible, the use of this tire should cease immediately.
Tires exhibiting irregular wear can be at risk for a blow-out, which in turn, can cause a wreck. This is especially true of any tire with cord or belting material visibly showing.
Driving on tires in this state can be extremely hazardous, and can significantly increase one’s chance of being injured in a wreck. Therefore, periodic tire inspection is of the highest importance, and can even save lives in certain cases.
If in doubt, it is always better to discontinue the use of a particular tire, rather than risking your safety, or the safety of your family. Though tires can be relatively expensive, they are worth every penny when one’s life is on the line.
What If Only One Tire is Wearing on the Outside?
If you notice that only one of your tires is wearing on the outside edge, it’s most likely that the tire in question is underinflated.
Using a tire pressure gauge, make sure the PSI matches (or is near to) the manufacturer’s specifications (found on the driver’s side door jamb or in the owner’s manual). While that’s the most common scenario, any of the other four causes listed above may also be the culprit.
Do Tires Wear Faster on the Outside?
Unless you’re involved in car racing in some form and have a custom alignment setup, no, tires do not wear faster on the outside. Under typical driving conditions, your tires should wear evenly across the tread.
But in general, front tires (that do most of the work) will wear faster (especially along the edges) than rear tires. Now if you drive a rear-wheel-drive car and are a regular on Friday nights at the dragstrip, or enjoy doing the occasional burnout or donuts, you can obviously dispute that.
How to Prevent Tires From Wearing on the Outside
Proper Tire Inflation
To keep your tires from wearing unevenly, regularly check your tire pressure. Tires lose air naturally, so it’s important to ensure they are within the manufacturer’s recommended range.
Running on poorly inflated tires can lead to irregular wear patterns and reduced traction. Use a tire pressure gauge, and follow the guidelines found on the sticker inside your driver’s door jamb or in your vehicle’s user manual. Also, account for changes in weather or temperature, as they can affect the pressure in your tires.
Frequent Tire Rotation
Rotating your tires can help distribute wear evenly across all four wheels. It’s recommended that you rotate your tires every 5,000 to 7,500 miles, or at every oil change. This will help even out any differences in wear between the front and rear tires, ultimately extending their life.
Alignment Checks
Misaligned wheels often cause tire wear on the outer edges. Periodically checking your vehicle’s alignment can help prevent this issue. If you notice uneven or rapid tire wear, poor steering control, or that your car pulls to one side, it’s time for an alignment check.
Suspension Maintenance
Your car’s suspension system, including components like springs, bushings, and shocks, plays a major role in evenly distributing weight and providing traction for your tires. Worn or damaged parts can lead to irregular tire wear.
