Some car tyres are louder than others. Sometimes, you can blame that noise on your tread or blocks. Other times, tyre noise indicates that something’s gone wrong with your car. It’s important for drivers to know which tyre noises indicating damage and which ones are part and parcel of driving.
What is tyre noise?
Your car’s tyres can make all manner of noises while you’re on the road. Some kinds of tyre noise when driving are a normal part of the driving experience, while others are indicative of tyre damage. The most common tyre noises you’ll likely encounter as a driver include:
- Squeaking – Some tyre noise is a result of an aggressive driving style. If you take a corner too quickly or come to a stop without slowing your car down first, your wheels may squeak in protest. The good news is that this isn’t necessarily a sign of significant damage. The bad news is that if your tyres squeal too often, you’ll need to replace them more quickly than you would have, otherwise.
- Humming – Unless you’re driving a luxury sports car, your tyres probably make a bit of noise while you’re on the road. The most common type of tyre noise is the tyre hum. This humming normally doesn’t indicate that anything’s wrong with your tyres. However, if the humming increases in volume, becomes erratic, or otherwise veers away from your norm, you may want to have your tyres checked out.
- Thundering or “womping” - There’s no good way to describe the thunderous shuddering noise your tyres make when something’s gone really wrong. This “womping” noise tends to come on abruptly and is a sign that your tyres or their structural supports have been damaged. If your tyres start to thunder or “womp” while you’re on the road, pull over!
When do you need to worry about tyre noises?
As you may have guessed, you don’t always have to worry about the noises your tyres are making. Tyre noise is most often only concerning when paired with:
- A difficult-to-steer car
- Roadway drifting
- Additional clanking noises
- Decreased or bare tread
With that in mind, know that you don’t need to panic the moment your tyres start to make more or less noise than usual. You will, however, want to perform regular, at-home car maintenance to ensure that all of your car’s parts are appropriately aligned.
What causes tyre noise?
It’s not always damage that’ll cause your tyres to start making noises. Some of the most common causes behind your tyres various noises include:
- Air compression – as your tyres come into contact with the road, air rushes beneath your tread blocks and shivers your tyres, generating your typical amount of vehicular hum.
- Uneven tread wear – occasionally, your tyres will wear more so on one side than they will the other. If the tread on a tyre is uneven, it won't consistently come into contact with the road. As a result, it’ll be more difficult to maintain a smooth – or a quiet – ride.
- Alignment issues – if you’ve been taking your car out for longer drives, it’s likely that one or two have shifted out of alignment. When your tyres slip out of alignment, your ride will be bumpier and your air chamber – the source of your normal roadway hum – will produce more name.
- A damaged tyre – while most cars on the road today have built-in lights letting you know when your tyres are low on air, the tyres themselves have never been subtle. If a tyre pops while you’re on the road or you’ve violated your tyre speed index, you’ll hear it. Not only are cars with damaged tyres significantly more difficult to drive, but the “womping” noise that a burst tyre makes is almost impossible to ignore.
The quietest tyres
What is the acceptable noise level for a tyre?
Meeting the current noise levels required to obtain approval is not a problem for tyre manufacturers. The differences recorded during tests between individual tyres amount to an average of 6-8 dB (A). Many models (especially the quietest summer tyres) are 4-6 dB (A) below the limit, but a big part also approaches the limit at 2dB (A).
These limits are set out in Regulation No 117 of the United Nations Economic Commission for Europe (UNECE) - uniform provisions concerning the approval of tyres with regard to rolling sound emissions and/or to adhesion on wet surfaces.
The so-called decibel table is presented as follows:
For reinforced tyres (XL) the limits are higher by 1dB (A).
However, after tyre labels were made mandatory, the noise limits became more stringent. The division into classes by width changed as well. The new tyre classification is as follows now:
For reinforced (XL) and M+S tyres, these limits will be 1dB (A) higher.
Currently, the best noise category on tyre labels is awarded to models achieving 67 dB (one wave). 68 dB is also a great achievement (still one wave).
How are tyre noise and comfort tested?
There are many methods to determine tyre noise level and comfort. For noise assessment, methods similar to those used during tyre approval tests are usually applied.
Tyre noise tests should be carried out in a square-shaped test zone of 20m by 20m, with microphones located halfway at the distance of 7.5 m from the vehicle's axis of movement. The track should be made of aggregate with maximum size of 8mm.
How to reduce tyre noise?
Eliminating irritating tyre noise doesn’t have to be difficult. Sometimes, it’s as easy as replacing old tyres or experimenting with tyres that have directional tread. That said, it can be a challenge to eliminate tyre noise that’s indicative of damage throughout your axis and structural supports.
If you’re dealing with significant tyre noise and subsequent vehicular damage, you’ll need to take your car to the nearest garage for a proper diagnosis. It’s best to try and have a recording of your tyre noise on hand so you can more effectively explain what you’re dealing with to your local professionals.
With this extra information on hand, the experts at your local garage can realign your tyres, inflate your tyres properly, and otherwise explore your car to ensure that none of its parts are out of place.