Many drivers are confused or worried when they hear their car tyres squeal. This squealing noise when driving is often mistaken as a sign of something being wrong, but usually such a conclusion is far from the case.
So why do tyres squeal, really? Is it ok if you hear some kind of a squeaky noise when driving? Where does it come from and what should you do about it? Below we explore the processes that cause the tyre screeching sound effect or other types of tyre noise to help you understand what they may mean.
When does the tyre squeal sound effect occur?
Tyre grip requires slip and friction, both of which generate noise. When it comes to car tyres, we can distinguish between two forms of tyre squealing noise caused by the friction of rubber against the surface of the road.
- Hissing sounds
- Squeaking sounds
Hissing sound from car tyres
Hissing sounds of car tyres are formed during normal driving, when an average level of grip is required. It can appear when driving straight, during gentle braking, accelerating or cornering with a large radius and at a moderate speed.
Squeaking sound from car tyres
Squeaking sounds, on the other hand, appear when the level of grip is approaching the limit offered by the tyre and road surfaces. This sound of squeaking wheels can be generated during sudden emergency braking, strong acceleration or when making a narrow turn at high speed.
How is tyre squealing generated?
The mechanisms of car tyre squeaking can be best explained in the following diagram:
Based on the above figures, what happens when your tyres squeal is, basically, the following:
The block of tyre tread touches the road surface.
The block tilts more and more to maintain the contact point on the road.
During this step, energy is accumulated.
The block reaches the limit of the available grip and begins to slide,
gradually releasing energy. This starts generating vibrations until the block
leaves the contact patch.
The block tilts and starts to move.
The block moves so the initial points of contact are separated.
The block completely loses contact with the road surface and rapidly
straightens, releasing the previously accumulated energy. As it rubs against
the surface, the tread generates the car tyre screech sound effect.
What causes and influences the squeaking tyre sounds?
Your tyres’ squealing sound is caused by the coefficient of grip on a particular surface, as well as the speed and manner of the maneuver being performed.
Of course, since such noise is caused by the tread block, the tread pattern also matters, with the different number of blocks, grooves and lamellas all factoring in. In addition, the nature of the compound can also influence the level of noise produced. Furthermore, the tread depth, and tyre age can cause the blocks to become stiffer, changing the type of the noise produced.
Which tyres will squeak louder?
When it comes to tyres themselves, normally those with the least amount of grip will produce louder sounds. This sound can then be amplified by the type of surface you are driving on.
The volume will also be influenced by various other factors, such as the tread pattern of your tyres, wheel bearings, or certain car problems, e.g. the lack of wheel alignment or damage to the car suspension system.
Is car tyre screech dangerous?
Most of the time, the squeaky noise when driving is not a bad sign. It simply indicates the tyres are approaching (and soon passing) the border of tyre grip with the vehicle. In fact, it is often the opposite - the squeak, squeal or screech can be used to enhance preventive driving.
Experienced drivers are usually able to recognise the sound of their car tyres and identify the signs of potential problems. If you drive on the same tyres over a certain period of time, this noise may be a warning that they are getting used up.