midwstCostofLivg

This is an old post but I'm seeing a possible misconception here. The lightweight noise insulating glass option is lightweight first and tries to compensate for loss of thickness with sound insulation. As I understand, this option is actually louder than the base glass.

kayjh

I don't think that conclusion is correct. Porsche seems to say it can reduce noise transmission by about 15%. But the 911 model is just noisy, especially from tire roar, so it's a car best suited to people who don't mind some hearing loss over time. If the sound deadening material does what BlueHighways says, I wonder why Porsche doesn't offer it as an option to those who don't mind adding 50 lbs of weight in exchange for a car that is 10db quieter. I wouldn't want to apply this stuff to the outside of the car though (i.e. wheel well). I'm sure plenty of water gets into the area when driving in rain storms or through puddles and who knows where it will get trapped. Rust is always a concern.

midwstCostofLivg

I'm not so sure. They rate the thermally and noise insulated glass on 4 door models at 7% reduction - but that is not a lightweight glass option. https://newsroom.porsche.com/en/2021...401-26834.html

midwstCostofLivg

Nick Murray has also said that the 911 lightweight glass option is noisier than base. (during a review of 2 992's - one with and one without the option)

992.Turbo.S

The TTS has more sound deadening for sure and has much less road and tire noise then my GTS had.
In normal mode it is quiet, in sport mode or with the exhaust switched on it actually pipes engine noise into the cabin, this is what my dealer told me and it is definitely noticeable.

aquatone

...and I found the opposite. I have the noise-insulating glass in my C4S and compared it with a C2 with the standard glass and did not necessarily find my car *that much* quieter, rather the balance between tire/road noise and other external noise was altered, Road nose was more prominent in my car but passing trucks, wind noise etc less. This was over the same road surface to eliminate a variable.

Also, this glass was definitely marketed for its noise-insulating qualities over its lightness when I bought my C4S in 2021. This whole subject is so subjective and confusing, I have even started wondering whether there are two types of glass. One is lightweight (and noise insulating) for the T, GT cars etc, and the other is noise insulating (and lighter weight) in the C2, C4, Turbo etc. (And similar to what is in other models like the Panamera in the article above)

kayjh

Thanks, I stand corrected on the percentage. But having owned a 991.2 model without noise insulating glass, it was my impression that most of the tire roar was coming through the wheel wells rather than the windows. As this 911 model continues its journey from sports car to more of a GT, I won't be surprised if Porsche starts adding some sound deadening material to curb road roar. There will still be plenty of models ; GT3, T, etc. to cater to the true sport car enthusiasts while satisfying owner like me who prefer a quieter daily driver experience.

midwstCostofLivg

I'll add that when I upgraded from a 991 C4S to a 991 Turbo, there is a really big difference in cabin noise levels. The Turbo is much quieter. That's how I landed in this thread - looking for answers on what differences there might be, and recently was learning about the 992 glass options as I look to place an order. Here's the Nick Murray video where he mentions the lightweight glass being noisier, granted it's a GTS vs a CS, but the guys is very well versed in Porsche options so I expect he's taking that into account.