Tire noise amplified by aluminum chassis?

[ToddRLockwood]

Don't get me wrong, I love my Model S, but something I've been curious about even before I received my car... is the sound of the tires actually made worse by the aluminum chassis? I first noticed this while watching many of the first-drive videos. There is a particular acoustic note heard inside the car when it goes down the road. While the Model S is very quiet overall, the car seems to have a different ambient sound than a steel chassis sedan (minus any engine noise, of course). I wonder if the aluminum chassis has anything to do with this, and could Tesla potentially take further steps to deaden it. I'm a former audio engineer, so I tend to be hyper-aware of these things.

 

[mknox]

I do an awful lot of freeway driving at constant speed, usually with Cruise on. My Model S is definitely no quieter than my previous Cadillac CTS was in those conditions. Sometimes I think it may even be a bit louder, and I attribute it all to tire noise. There is very little wind noise (in either car) and the Caddy's engine was indiscernible unless I put my foot into it. Whether this has anything to do with aluminum vs. steel I couldn't say.

 

[ToddRLockwood]

No question that tires are where the noise starts, but how that noise gets transmitted through the suspension and frame is another story. Sound is easily transmitted when there's a physical connection—in this case: tire to wheel to suspension to frame. The aluminum frame, with its low density, would be less likely to attenuate noise and vibration than would steel. To a degree, the battery pack may help add some density. Another factor is the acoustic resonance of the interior. Every space has a particular resonance, and if the frequency of the tire noise happens to coincide with the interior resonance, the noise will be amplified.

 

[jerry33]

Also the road surface has a great deal to do with it. Certain tires with certain road surfaces can be really bad.

 

[ToddRLockwood]

I imagine the weight of the car and the relatively high tire pressures contribute as well. Perhaps this will lead to tire manufacturers developing quieter tread designs.

 

[mnx]

I imagine the weight of the car and the relatively high tire pressures contribute as well. Perhaps this will lead to tire manufacturers developing quieter tread designs.

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