tyre advice

[Bonefishblues]

Originally Posted by AndyV7o

Its to do with how the grooves of the tread pattern deflect the noise, the noise of a tyre is caused by air being compressed and expelled by the tread pattern and road surface, how the tread pattern is formed influences where and how this noise is emitted. I dont know more than that, but its a thing. The thing about deflecting tyre noise inward was said by someone in the industry, and Im repeating it.

So a lower dB rated tyre has been designed to channel noise inwards, which then travels up through the rims through the suspension, or via the wheel arches, and into the cabin in order to reduce the external dB rating?

[AndyV7o]

Not necessarily, but that -can- be the case, it is one of a multitude of ways to keep exterior noise down.
Thats why I said the noise lable may or may not represent interior noise.
One tyre might just be plain quiet, one may be quiet as the vehicle passes but one hell of a din inside, one may be quiet inside but very loud as the vehicle goes down the street, one may just be downright noisy full-stop.....

[Bonefishblues]

So lower dB is better. Because less noise.

[XC90Mk1]

Originally Posted by AndyV7o

Not necessarily, but that -can- be the case, it is one of a multitude of ways to keep exterior noise down.
Thats why I said the noise lable may or may not represent interior noise.
One tyre might just be plain quiet, one may be quiet as the vehicle passes but one hell of a din inside, one may be quiet inside but very loud as the vehicle goes down the street, one may just be downright noisy full-stop.....

No it does not. Tyres are generally non asymmetrical, look at Goodyear efficient grip for example, it may be fitted either way round so producing noise left or right is not possible.

Noise is ludicrously complex to define, at source, break out, 1m away and at what rotational speed (there will be ‘modes’ throughout the frequency range that occur at various points). Tyre manufacturers do not channel into cabin.

[XC90Mk1]

Originally Posted by XC90Mk1

No it does not. Tyres are generally non asymmetrical, look at Goodyear efficient grip for example, it may be fitted either way round so producing noise left or right is not possible.

Noise is ludicrously complex to define, at source, break out, 1m away and at what rotational speed (there will be ‘modes’ throughout the frequency range that occur at various points). Tyre manufacturers do not channel into cabin.

Also noise wil be muasured in a lab not on a vehicle on the road. Manufacturers have no incentive to put into cabin and it is doubtful they could anyway.

[Bonefishblues]

Originally Posted by XC90Mk1

Also noise wil be muasured in a lab not on a vehicle on the road. Manufacturers have no incentive to put into cabin and it is doubtful they could anyway.

Remarkable engineering if they could, eh?

[XC90Mk1]

Originally Posted by Bonefishblues

Remarkable engineering if they could, eh?

Unbelievable yes.

[AndyV7o]

*sigh*
Right, no-one said anything about directing sounds left or right, directional or assymetric tread patterns, etc.
Noise is predominantly down to tread pattern and air.
How the tread pattern is created influences where noise is emitted.
Tyre labelling noise rating is for EXTERNAL DRIVEBY NOISE.
These last 3 sentences are factual, non-negotiable, things.

I dont know -exactly- how this pans out, I just know that Im a tyre nerd, who frequents tyre sites and forums, and is moderately familiar with the owner of a tyre review/magazine site, amongst other things. This info comes mostly via the site owner who has a very good working relationship with numerous tyre manufacturers such as Michelin, Goodyear, Continental...
As said, I dont know the full why's and wherefore's of noise deflection etc, but I'm conveying genuine info from genuine sources, its not my opinion! 👍 😙

[Bonefishblues]

So lower dB rating means lower noise which is good - or is that proposition incorrect?

[AndyV7o]

Heeheehee...
Alright fella, here goes...
Low dB lable rating means a quieter tyre to those in the outside world around the vehicle as it passes by. Thats it.
It might also be quiet inside the car, but it might also be really noisy, or, anywhere inbetween. Thats it.
The governing bodies only care about exterior noise, not interior noise. Thats it.

Done.

👍👍😙