Rightfully so, finding the right tyre tread for your car is a crucial component of the tyre selection process. After all, tyres are the only point of contact between our vehicle and the road. The choice of tyre tread can affect both, the properties of the specific tyre, and the handling of the vehicle itself.
The right choice of car tyre tread can help with:
- Improving the amount of traction
- Improving the vehicle’s ability to steer
- Increasing the durability of the tyre itself
Similarly, the right choice in tread patterns can influence a number of key factors, including driving comfort, tyre noise level, and fuel consumption rate.
Let’s take a look at the most important tyre tread features to consider before purchase, including the patterns, constructions, and types of tyre tread. By identifying these ‘driving’ factors, you will understand how a tyre is designed to address specific requirements.
For a comprehensive overview, take a look at the following video from our Oponeo team.
Tyre tread features
Sipes: These are the narrow voids and passageways on the tyre lugs, usually of 0.3 - 1.5mm width. Their main purpose is to improve the tyre’s traction on wet surfaces, including snow, by channeling water from underneath the tyre. This helps to build resistance against aquaplaning.
Tread lugs: This is the main element of the tread, into which many of the features are added and carved. The tread lugs’ main purpose is to provide good traction.
Tread rib: Also known as transverse voids, these are circumferential ribs or contact bars that encircle the tyre tread.
Tread groove: These are the depressed parts of the tread, similar to sipes, but often much longer and deeper. These grooves form a specific pattern, the shapes and sizes of which are calculated to enhance a given quality of a tyre. Generally, these features serve to improve the braking effectiveness and steerability of a tyre. The depth of the grooves, as well as their pattern, can also have an impact on the rolling noise level.
Dimples: Although not always present, dimples are often included to improve tyre cooling.
Tread voids: Similar to sipes, these voids create the space required to channel water from underneath the tyre when driving in the rain. This maintains good traction since the water exits through the wider voids along the axis.
The relationship between tread voids and tread lugs directly influences the overall contact area of a tyre. A larger number of voids can, for instance, offer better performance on wet surfaces, however, it simultaneously diminishes a tyre’s grip on dry surfaces. As a result, the number of voids is entirely dependent on the tyre’s purpose - certain wet or ‘rain tyres’ may feature more tread voids.
An overview of the basic tread elements
Tyre tread patterns
After this general overview of the most important tyre tread features, the next step is to take a closer look at the fundamental patterns used in tread designs. This section explains how the layout of all the tyre tread elements is calibrated to form a whole.
Depending on how this is done, a tyre can have two distinct parameters. The most common example is perhaps that of how winter tyres and summer tyres are often very different.
Rib pattern
Parallel S-shaped voids along the axis.
Rib pattern
The pros:
- Lower rolling resistance
- Good directional stability
- Good steering control (thanks to lateral resistance)
- Suitable for sustaining high speeds (thanks to low heat generation)
The cons:
- Poor grip when accelerating or braking on wet roads
- Flexing of the treads can cause excess stress, resulting in a tyre that is more susceptible to cracking
Uses:
These tyres are generally designed for use on hard road surfaces, such as tarmac and concrete. They are often fitted to the front or rear wheels of trucks and buses, depending on the drivetrain.
Lug shape
This pattern refers to a series of grooves that are perpendicular to the tyre’s circumference.
Lug shape
The pros:
- Improved traction
- Excellent grip when braking and accelerating
The cons:
- Excess noise at high speeds
- Not suitable for high speed driving due to additional rolling resistance
Uses:
Such tyres are generally designed for dirt roads, and so may often be found in 4x4 tyres. Likewise, they can often be seen on the rear wheels of trucks and buses, as well as all-terrain vehicles.
Mixed rib-lug shape
A mixed shape pattern is, as the name suggests, a combination of the two previous shapes. It can feature varying combinations of S-shaped voids along the axis, as well as perpendicular grooves.
Mixed shape
The pros:
- The central rib provides good directional control
- The shoulder lugs offer good braking & driving power
The cons:
- The mixed shape offers a more balanced performance, so it is not as good in key areas as the more specialised designs, such as pure rib or lug patterns
Uses:
These tyres are suitable for paved and dirt roads. They can be found on a variety of trucks and buses.
Block shape
A block shape pattern refers to designs with independent blocks along the tread, separated by a series of interconnected grooves.
Block shape
The pros:
- Good steering and stability on both wet and snow-covered roads
- Good water dispersal properties thanks to the numerous grooves
The cons:
- Low durability, depending on the size of the tread blocks
Uses:
The main benefit of these tyres is their ability to perform well on snow. This makes them highly useful as winter tyres, as well as all-season tyres for passenger cars.
Asymmetric shape
An asymmetric tyre tread is very common in commercial tyres, and refers to tread patterns that differ on each side. Typically, bigger blocks are used on the outer side, while the internal blocks are smaller. A series of grooves help disperse water outwards.
Asymmetric shape
The pros:
Good for high speed cornering thanks to the larger contact area
Reduced tread wear on the outside of the tyre
Improved stability when turning, thanks to the bigger blocks
The cons:
Uses:
These tyres offer great performance even at high speeds, making them suitable for sporting vehicles and more aggressive driving styles. Naturally, they are commonly used as motorsport tyres.
Directional pattern
Directional tyre treads are another common tyre design. They involve a series of lateral grooves positioned at the same angle on either side of the tyre. This creates a ‘direction’ of sorts, as all grooves point forward.
Directional pattern
The pros:
- Very good traction and braking
- Good water dispersal for stability on wet roads
- A good choice for fast driving styles
The cons:
- Due to their directional nature, these tyres need to be installed with the correct orientation
Use:
Directional tyres have plenty of uses, and they are most frequently found in performance passenger vehicles.
There is a massive amount of work that goes into designing a great tyre, and the details in the tread certainly matter to a lot. Once you understand how each factor contributes to the effectiveness of a tyre, you can readily identify what conditions a given set of car tyres is designed for.