A Deep Dive into Tire Treads: Safety and Legality

Safety and legality are two critical aspects every driver must consider, especially when it comes to the condition of their vehicle’s tires. One essential feature that determines both these factors is tire tread. It may seem like just a patterned exterior, but tire tread plays a crucial role in maintaining traction and preventing accidents.

In this article, we will delve into what lies beneath the surface of your tire, the significance of the minimum legal tread depth, and the consequences of ignoring these critical elements of vehicle safety.


What is Inside a Tire?

A tire, seemingly simple, is actually a complex structure with numerous components that contribute to its functionality and durability. Beginning with the outermost layer, the tread is the part that comes into direct contact with the road, designed with grooves and patterns to maximize traction and control.

Beneath the tread is the casing, comprising one or multiple layers of fabric known as plies. These provide structural strength to the tire, allowing it to resist internal pressure. Some tires may also contain steel belts, located under the tread area, which offer additional puncture resistance and tread stiffness.

Washed renewed tires on a sunny street near the shop.

The sidewalls, located on either side of the tire, are responsible for carrying the load of the vehicle, while the inner liner, made of impermeable rubber, retains the air inside the tire. Lastly, at the very center of the tire, you’ll find the bead, which ensures the tire stays attached to the rim.

What is the Minimum Legal Tread Depth?

Tread depth plays a crucial role in tire safety, ensuring adequate traction, and allowing the tires to expel water in wet conditions to prevent aquaplaning. As the tire wears down, the tread depth reduces, leading to decreased performance and safety.

Legal requirements vary by country, but in many places, including the United States, the minimum legal tread depth is 2/32 of an inch (or 1.6 millimeters). This is measured in the tread grooves that are around the tire’s circumference. Regular checking of tread depth is a legal requirement and should be a part of routine vehicle maintenance to ensure safe driving conditions.

It’s essential to note that even if your tread depth is right above the legal limit, it might still be a good idea to replace your tires. Safety organizations often recommend replacing tires when they reach a tread depth of 4/32 of an inch, especially for those driving in wet or snowy conditions, as the increased tread depth provides better traction and braking capabilities.

Cords Showing on Tires – What Does it Mean?

When you see cords or wires showing on your tires, it’s a significant cause for concern. The cords, usually made of steel or fabric, are embedded in the rubber of the tire to provide structural support and strength.

They’re located beneath the tread and the outermost layer of rubber. If the cords are showing, it means that the tread depth has worn away to the point that the inner structures of the tire are exposed, making it extremely unsafe. It’s an urgent indication that the tire must be replaced immediately.

What Causes Wire Showing on Tire?

1.     Excessive Wear

This is the most common reason why cords may be showing on your tires. Simply put, when a tire is used past its functional lifespan, the tread that protects the cords from the road gradually wears away.

Tire wear with little tread showing.

Over time, the relentless friction between the road and the tire will cause the rubber to erode, eventually exposing the cords beneath. Regular tire rotation can help prevent excessive wear on a single tire and extend the overall lifespan of your set of tires.

2.     Incorrect Tire Pressure

Tire pressure significantly impacts tire wear. Over-inflated tires are more susceptible to damage from road hazards like potholes and debris, and the center of the tire will bear most of the vehicle’s weight, leading to rapid tread wear in that area, eventually exposing the cords.

Under-inflated tires, on the other hand, cause the tire’s outer edges to contact the road excessively, wearing them down quicker and leading to potential cord exposure. Regularly checking and adjusting your tire pressure can help avoid these issues.

3.     Misalignment

Improper wheel alignment can lead to uneven tire wear. When the wheels aren’t aligned correctly, one or more tires can be at an angle relative to the road surface, which can cause one side of the tire to wear down quicker than the other. Over time, this uneven wear can lead to the cords becoming exposed.

4.     Aggressive Driving

Frequent hard braking, fast acceleration, and sharp turns can put a lot of strain on your tires, leading to rapid wear and potentially exposing the tire cords. Driving smoothly and responsibly can significantly extend the lifespan of your tires.

5.     Faulty Suspension or Brake Components

Coil spring and shock absorber on the service shop.

If your car’s suspension or brake components are worn or damaged, it can lead to excessive tire wear. These components are designed to evenly distribute weight and force across the tire. If they aren’t functioning correctly, it can lead to uneven weight distribution and rapid tire wear in certain areas.

6.     Road Conditions

Poor road conditions can take a toll on your tires. Potholes, debris, sharp curbs, and rough road surfaces can cause damage to your tire’s tread, and over time, may wear down the rubber enough to expose the cords.

7.     High Temperatures

In very hot climates, the road surface can become hot enough to speed up tire wear. The heat can make the tire rubber more malleable, leading to more rapid wear and potentially exposing the cords. It’s crucial in these climates to regularly check your tires for signs of excessive wear.

8.     Improper Tire Mounting

If a tire is not mounted correctly onto the wheel, it can cause irregular wear patterns on the tire. The tire might not sit evenly on the road surface, leading to certain parts of the tire wearing down quicker than others and potentially exposing the cords. It’s important to have your tires mounted by a professional to avoid this issue.

How to Prevent Cords from Showing on Your Tires

1.     Regular Tire Rotation

Regular tire rotation is one of the most effective ways to prevent excessive tire wear. Each tire on a vehicle wears differently due to factors like vehicle weight distribution and drive mode. By regularly rotating your tires, you ensure that the wear is evenly distributed across all tires, prolonging their lifespan and preventing the cords from showing prematurely.

2.     Maintaining Correct Tire Pressure

Maintaining the right tire pressure is crucial. Over-inflation can lead to rapid center tread wear, while under-inflation can cause accelerated wear on the outer edges of the tire. It’s recommended to check your tire pressure at least once a month and before long trips. Always inflate your tires according to the vehicle manufacturer’s guidelines.

A man checking the valve for tire pressure.

3.     Proper Wheel Alignment

Getting your wheels aligned regularly can prevent uneven wear that could lead to cord exposure. Misaligned wheels can cause tires to wear more on one side, leading to an imbalance that, over time, could reveal the cords. Professional wheel alignment ensures your tires meet the road at the correct angle, distributing wear evenly.

4.     Smooth and Responsible Driving

Aggressive driving behaviors, such as hard braking, sharp turns, and quick acceleration, can cause accelerated tire wear. Adopting a smoother driving style can significantly reduce the strain on your tires, help maintain their integrity, and keep the cords from showing prematurely.

5.     Regularly Checking Suspension and Brake Components

Regularly inspecting and maintaining your vehicle’s suspension and brake components can help prevent excessive or uneven tire wear. Faulty components could lead to uneven weight distribution, causing certain areas of the tire to wear down faster. Regular vehicle maintenance can help identify and address these issues before they lead to severe tire wear.

6.     Being Mindful of Road Conditions

Taking note of the road conditions you frequently drive on can help prevent rapid tire wear. Try to avoid roads with potholes, sharp curbs, or excessive debris, and if it’s unavoidable, drive carefully to minimize potential damage.

7.     Seasonal Tire Change

If you live in a climate with hot summers or harsh winters, consider changing your tires according to the season. Summer tires are designed to withstand higher temperatures, while winter tires are designed to provide better traction in cold, snowy, or icy conditions. Using the right tire for the season can prevent excessive wear and tear.

8.     Professional Tire Mounting

Mechanic changing the car tire.

Ensuring your tires are mounted correctly can prevent irregular wear patterns that could lead to cord exposure. If a tire isn’t correctly seated on the rim, it may wear unevenly, causing the cords to show prematurely. Always get your tires mounted by a professional to ensure they are fitted correctly and safely.

Is It Bad To Drive On A Tire With Little Tread?

Yes, it’s quite dangerous to drive on a tire with little to no tread. The tread on a tire enhances traction and allows water to escape from under the tire, reducing the risk of hydroplaning in wet conditions. When tread depth decreases, the tire’s ability to perform these functions also diminishes.

Tires with little tread have reduced grip, leading to longer stopping distances and a greater risk of skidding, especially in wet or icy conditions. Moreover, tires worn down to such an extent are at a higher risk of damage from road hazards like potholes or sharp objects, which could lead to sudden tire failure while driving.

Additionally, driving on such worn tires can also lead to legal issues. Most jurisdictions have legal minimum tread depths and driving with tires that don’t meet this requirement could lead to fines or other penalties.

How Do You Know If Your Tread Is Bad?

Tire tread depth is the primary indicator of a tire’s health. Here are some ways you can check if your tread is bad:

1.     Tread Depth Gauge

A tread depth gauge is a tool that accurately measures the tread depth in millimeters or 32nds of an inch. A reading of 2/32 inch or less indicates that the tire is legally worn out in most jurisdictions.

2.     Penny Test (or similar coin tests)

This is a simple and commonly used method to check tread depth. In the U.S., place a penny into the tread grooves with Lincoln’s head pointing downwards. If you can see all of Lincoln’s head, your tread depth is less than 2/32 inch, indicating that the tire needs to be replaced. Note that this method might not be accurate, and it’s always better to use a dedicated tread depth gauge.

3.     Tread Wear Indicators

Modern tires come with built-in tread wear indicators. These are small bridges that form between your treads. When the tread is worn down to the same level as these indicators, it’s time to replace the tire.

4.     Visual Inspection

Look for any visible signs of excessive wear or damage, such as bulges, cracks, or punctures. Also, check for any irregular wear patterns, as this could indicate a problem with your alignment or suspension.

What Is A Bad Tire Tread Number?

Tire tread is typically measured in 32nds of an inch. In most jurisdictions, including the U.S., the legal minimum tread depth is 2/32 of an inch. So, if your tire tread measures this or lower, it is considered a “bad” tire tread number and indicates that the tire needs to be replaced.

However, many safety experts recommend replacing your tires when they reach a tread depth of 4/32 of an inch, especially if you drive in wet or snowy conditions. Even though the tire might be legally acceptable at this depth, its performance in terms of grip and water dispersal is significantly compromised, potentially making your vehicle unsafe to drive.

What Is The Function Of The Tire Tread?

The tire tread is the patterned outer layer of a tire that comes into direct contact with the road. It has two main functions: providing traction and expelling water. The grooves in the tread pattern grip the road to maintain control and stability, particularly during cornering and braking.

They also channel water away from the contact patch between the tire and the road in wet conditions, reducing the risk of hydroplaning. As the tread wears down over time, these capabilities are reduced, which is why it’s important to replace tires when the tread depth gets too low.

What Is The Purpose Of The Steel Belts In A Tire?

Steel belts are layers of steel cords coated with rubber, located just beneath the tread area in most modern radial tires. They serve two main purposes: they provide structural strength to the tire, enhancing its durability and puncture resistance, and they assist in maintaining the shape of the tread, which helps to improve traction and treadwear.

By stiffening the tread, steel belts reduce rolling resistance, which can enhance fuel efficiency, and they also distribute heat generated during driving, helping to prolong tire life.

How Does Incorrect Tire Pressure Lead To Wire Showing On The Tire?

Incorrect tire pressure either too high or too low – can cause uneven or accelerated tire wear, which may eventually expose the tire cords. Over-inflation causes the tire to be more rounded, resulting in the center of the tread bearing most of the load and wearing out faster.

Underinflation, on the other hand, causes the tire’s edges to make excessive contact with the road, wearing them down quicker. Both situations can lead to the tread wearing thin enough to expose the underlying cords or wires.

Why Is Aggressive Driving Harmful To Tires?

Driving car at high speed.

Aggressive driving behaviors, such as hard braking, fast acceleration, and sharp turns, can put a lot of strain on your tires. These actions generate excessive heat and cause the tires to wear down rapidly. Over time, this can wear the tread down to the point where the underlying cords or wires become exposed, increasing the risk of a blowout or other tire failure.

How Does Tire Rotation Help In Extending Tire Life?

Tire rotation is a practice that involves moving tires from one position to another on the vehicle – typically front to back and side to side – to ensure even tire wear. Each tire on a vehicle carries a different amount of weight and performs different steering and braking functions, leading to unequal wear rates.

Regularly rotating the tires helps to balance this out, spreading the wear more evenly across all four tires, which can prolong their overall lifespan.

What Is The Importance Of Using The Right Tires For The Season?

Using the right tires for the season can significantly enhance vehicle performance and safety. Summer tires are designed to perform best in warm conditions, providing excellent traction and handling.

Winter tires, on the other hand, are designed to perform well in cold, snowy, or icy conditions. They are made from a softer rubber compound that retains flexibility in cold weather, and they have tread patterns designed to grip onto snow and ice and channel slush away from the tire.

Using the appropriate tire for each season can prevent excessive wear and help to maintain optimal performance.

How Can One Visually Inspect Their Tires For Signs Of Wear Or Damage?

Visual inspection of tires involves looking for signs such as low tread depth, irregular wear patterns, cracks, bulges, or punctures. To check the tread depth, one can use the penny test, a tread depth gauge, or look for the tread wear indicators built into most modern tires. Irregular wear could be seen as uneven wear on one side of the tire or in the center.

Cracks could appear on the sidewalls, and bulges could indicate internal damage to the tire. Punctures or objects embedded in the tire should also be noted during a visual inspection.

What Could Be The Implications Of Driving On A Tire With Cords Showing?

Driving on a tire with cords showing is extremely dangerous. The cords are part of the internal structure of the tire, and when they’re exposed, it means the tread has worn away completely, severely compromising the tire’s ability to provide traction and resist punctures.

This can lead to loss of vehicle control, particularly in wet conditions due to an increased risk of hydroplaning. It also puts the tire at risk of sudden catastrophic failure, such as a blowout, which can be particularly dangerous at highway speeds.

How Does Wheel Alignment Contribute To Tire Wear?

Wheel alignment involves adjusting the angles of the wheels so they are correctly positioned relative to the vehicle’s suspension and each other. Misaligned wheels can lead to uneven tire wear. For example, if the wheels are “toed in” or “toed out” (pointing inwards or outwards relative to the vehicle), the inner or outer edges of the tires could wear down more quickly.

Wheels alignment camber check.

Similarly, if the wheels have too much positive or negative camber (tilted away or towards the vehicle), one side of the tire can wear down faster than the other. Regular wheel alignments can help ensure even tire wear and prolong the lifespan of your tires.

What’s The Link Between Temperature And Tire Wear?

High temperatures can accelerate tire wear. As the temperature rises, the road surface can become hot enough to increase the wear rate of the tire rubber. The heat can make the rubber more malleable, causing it to wear down more quickly.

Furthermore, heat can cause the air inside the tire to expand, potentially leading to over-inflation if not monitored, which can also cause rapid tread wear.

How Often Should Tire Pressure Be Checked?

Tire pressure should be checked at least once a month and before any long trips. However, if you often drive in severe conditions or drive a commercial vehicle, it might be advisable to check the pressure more frequently.

Remember, tire pressure should always be checked when the tires are cold, as heat from driving can cause the pressure inside the tire to increase, giving an inaccurate reading.

Why Should I Avoid Driving On Roads With Poor Conditions?

Roads with poor conditions, like potholes, sharp curbs, or excessive debris, can cause damage to your tires. This damage could lead to uneven wear or punctures that could result in rapid loss of air pressure or even a blowout. Avoiding these conditions, or at least driving carefully when they can’t be avoided, can help to prolong the lifespan of your tires.

Why Are There Different Tire Tread Depth Recommendations For Different Driving Conditions?

Different driving conditions require different amounts of tread for optimal safety and performance. In dry conditions, less tread is needed to maintain good traction. However, in wet or snowy conditions, more tread depth is necessary to channel water or snow away from the tire’s contact patch with the road, reducing the risk of hydroplaning or snow packing.

Therefore, many safety experts recommend replacing your tires when they reach a tread depth of 4/32 of an inch if you often drive in wet or snowy conditions.


In summary, the condition of your tires is crucial to the overall safety and performance of your vehicle. Regular maintenance such as correct inflation, rotation, and alignment, along with seasonal changes and proper mounting, can help ensure your tires remain in good shape for as long as possible.

Keep in mind the minimum tread depth for safe driving and be proactive in checking and replacing your tires when needed. It’s always better to be safe than sorry when it comes to your vehicle’s tires, as they are the only parts of your vehicle that make direct contact with the road. Drive safe!

Avatar photo
About Brock Rangel

Hi, I am Brock, and I am the lead editor/photographer for TheCarColony. I have been a mechanic for over 14 years now, and I am here to spread my car knowledge across the web!