Why Do Tires Have Grooves: What I Wish I Knew

Grooves or tread patterns are the rubber patterns bordering a tire that make contact with the surface while driving. Although extremely important for road safety, this element is mostly ignored or overlooked by vehicle owners.

When speeding, it is these ridges and grooves which prevent a vehicle from spinning out of control. And here’s a scary stat for you – experts suggest that more than 200 people die every year in car accidents related to weak tire treads!

So in today’s article, we’ll be discussing the importance of the different parts of a tire tread, the different types of tread designs, and what makes them vital for driving safely.

What Is the Purpose of Ridges And Grooves in the Tire Tread?

Let’s start with the four integral parts of a tire tread:

  • Tread Blocks: raised rubber segments that come in contact with surfaces.
  • Ribs: raised segment of a tread pattern that consists of tread blocks.
  • Sipes: thin, small slots cast into the tread blocks.
  • Grooves: deep channels running laterally and circumferentially around the tire; specifically designed to drain and expel water from underneath the tire to prevent hydroplaning. 
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Altogether, these four constituents are arranged in a distinctive pattern that regulates and determines a tire’s specific performance in terms of noise, traction, handling, dry and wet braking, hydroplaning, resistance, and tread wear. 

As mentioned, grooves are of particular importance. This is because they enhance traction on wet surfaces by promoting water removal from beneath the tires, and also help attain better friction in wet conditions. 

Why Are Tread Patterns So Important? 

Now that we’ve summarized the importance of the various parts of a tread pattern let’s go into the details of why they are so important.

Better Handling

Tire treads immensely influence handling and steering. Every unique tread pattern has a different function and results in different driving outcomes.

For instance, symmetrical tread patterns are meant for driving on the highway. In contrast, asymmetric tread patterns are designed to drive on wet, slippery roads – but more in the upcoming section.

Fuel Economy 

Tread patterns can also influence your vehicle’s fuel-consuming efficiency. 

This can help you save money and protect the environment since reduced fuel consumption means fewer carbon footprints.

Acceleration and Braking

Maintaining tire treads also promotes safe and smooth acceleration, ensuring your vehicle doesn’t lose grip on the road spin out of control.

Regarding braking, it is always preferred that a vehicle must stop quickly and in the shortest distance, especially on wet or snowy surfaces. As mentioned earlier, tire treads also play an important role here, reducing hydroplaning and allowing your vehicle to brake swiftly. 

Grip and Traction

And lastly, tire treads allow a vehicle to retain grip and traction, ensuring a safe and smooth driving experience.

If the tires are extremely smooth or worn out, the vehicle will have less traction, and when these tread-less wheels come into contact with a wet or icy surface, there is an extremely high chance of the vehicle slipping out of control and off the road.

Why Do Tires Have a Tread Pattern?

So to summarize, tires have tread patterns because they:

  • provide increased tractive force and friction on the driving surface
  • grooves are specifically designed to expel water from beneath the tires, which prevents slipping
  • help mitigate roadway noise
  • enhance grip on soft or loose surfaces
  • help save the amount of rubber used in manufacturing tires on a large scale

What Are the Different Types of Tread Designs? 

Broadly speaking, there are three kinds of tire tread patterns.

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Asymmetrical Tread

An asymmetric pattern features two different tread designs; one on the outer half and the other on the inner half of the tires. They are a popular choice for ultra-high-performance vehicles. 

PROS:

  • Exceptional handling
  • Reduced noise
  • Enhanced curve stability on dry surfaces 
  • Reliable grip in wet conditions 
  • Meant to mitigate hydroplaning

CONS:

  • Lesser flexibility for tire rotation 

Symmetrical Tread

This is the most common type of tread pattern and is suitable for passenger cars. This design features independent tread blocks or continuous ribs across the entire face of the tread. Also, both halves of the tire have the same pattern.

PROS:

  • Smooth, quiet, and comfortable driving experience 
  • Enhanced directional stability
  • Low rolling resistance
  • The steady grip on dry surfaces 
  • Flexibility for tire rotation
  • Long-lasting
  • Fuel-efficient 

CONS:

  • Less adaptable to changing road conditions
  • Not suitable for high-performance vehicles
  • Not very effective on wet surfaces 

Directional Tread

A directional tread pattern is meant to roll forward in a particular direction only and is more sporty. The lateral grooves meet in the center of the tread and resemble an arrowhead.

They are usually featured on all-season or winter tires and are useful for high-performance vehicles.

PROS: 

  • Enhanced and efficient protection against hydroplaning due to V-shaped grooves
  • Exceptional handling and extra traction on mud and snow
  •  Extremely good road holding at high speeds

CONS:

  • Tire rotation is complicated since they can only be rotated vertically

Best Way to Maintain Tire Treads

There are several ways to maintain tire treads and know when to replace or retread your tires.

The Penny Test

A penny can tell you if your tires have reached a depth of 2/32 inches which indicates that they need changing.

Simply put a penny straight onto the ridges of your tire. If the top head of the penny is still detectable, you should change your tires.

But if the top head disappears, you can wait for a little while before replacing your tires.

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Tire Rotation

Front tires wear out rather quickly as compared to rear wheels. By rotating tires after about every 5000 miles, you can equalize uneven tread wear and extend tread life.

Wheel Balancing 

Tires feature-heavy spots, which can result in excessive tread wear and vibration.

So when you have your tires rotated, it is also important that a mechanic balances your wheels. Plus, it is cost-effective as compared to buying new wheels!

Final Thoughts

As your vehicle gains mileage, the tread on your tires begins to wear out. This can have life-threatening and dangerous consequences, which is why it is crucial to monitor and maintain your tire treads.

Also, to ensure maximum safety and optimal performance, do not mix tire tread patterns. Instead, when replacing tires, it is preferred to source the same model and make of tires you already had; this guarantees and preserves performance characteristics.

ABOUT THE AUTHOR

Dean Alvarez, TireForge Head Author

Thanks for reading our article! We've written this article with a lot of thought and care. If you're interested in seeing more of our content, please check out our Tires section and find an answer to your questions!