ffejrey

I can sum up my reply very confidently - If I had the opportunity to drive any speed I wanted I surely would not be driving 75 with the cruise control on!

Thank you for you reply and a frame of reference is always enlightening.

While smaller wheels will always be more quiet they also dramatically compromise the performance capabilities of our saloons.

What I am personally seeking in this thread are 2 things:

1. Validation that others experience what I have in 4 A8's
2. I/We find the root cause of the resonance/harmonic so we can mitigate it if we choose/can.

Take my car for example. However odd it may be, my drive shaft was installed off 180 degrees before I purchased the vehicle. This caused the car to have amplification of the same harmonic Audi is claiming to be tire noise. This harmonic also causes the front struts to sometimes "bonk" with the same frequency of the harmonic, is inconsistent and to me sounds like a cheap car. Simply put, if the drive shaft contributes to what Audi claims is "tire noise" what else does. To me it seems obvious the connection is that both the tires and drive shaft cause vibration which is translated to Audi components of the vehicle. It would make sense with the amplification of my issue that there is a weak point of the vehicle which is acting as a "tuning fork" for multiple vibrational sources.

Finally the noise I am hearing is only from the front of the vehicle. If it were truly tire noise, we would be able to hear something from the rear.

So again in summary, if I could drive 100+mph every day and make the sound go away I would do just that. However the choice I am faced is purchasing 19" tires which change the dynamics of the car significantly and is a huge compromise. I would like to search deeper, and understand more.

The A8 is a flagship sedan and published as one of the quietest. It therefore should be both quieter than the average bear (including the A6), and also perform beyond expectations. Right now in my experience you have to make a choice of one or the other. This is unacceptable. Why do you think Audi spent so much time and attention on this "issue" and also tout correcting it on the 2015?

ffejrey

So I just had an interesting convo with the same product service engineer I did prior at Continental tires, what a wonderful human being.

He confirmed a few things, mainly - if I have heard the same frequency and 'nature' sound with different tires, the sound is not tire noise.

He also told me that Continental just finished developing and have started to roll out a new tire which is an "AO" (Audi OEM). It is called "contisilent" and decreases the volume of tire noise by 7db. This is the tire new A8's should have if not Pirelli. Basically there's a dense foam glued to the inside of the tire of the contisport 3's.

So... with the addition of mass dampeners and everything else on the 2015 we can scientifically conclude the A8 car itself has harmonic issues in addition to tire noise, the tires only increase amplitude. Again, the addition of mass dampers proves this. Audi is grasping every band aid it can to soften the problem, which unfortunately means there is no easy fix for us.

However by Audi telling its customer the noises they experience are wholly "tire noises" is simply untruthful. For Audi to tell me if I do not want to hear their NVH issues I have to spend $5000 is unethical. The least Audi can do is admit the issue so it's owners are aware and can make informed decisions. Call it a "design characteristic" or some other legal wording, just don't pull the wool over our eyes...

needles

I just listened to your YouTube video again. What phone did you use to record the sound? I made a video on my phone at these speeds and I could not hear a thing, but when I play the video back the automatic gain control on the phone amplified everything to a point where I could hear every imperfection in the pavement and each lug in the road thunderously (these are things that are so faint when I drive I don't even notice, I've lauded the A8 as the quietest vehicle I've ever been in).

I'll try and make a better recording today. I need to go and vote this morning and will be doing a brief highway stint on the way to the election commission office.

Bladerunner

I have the humming sound too. Dealer blamed tyres. I brought new tyres, still hums.
I think it's the oil in the air suspension, try using the firmer settings and see if the pitch goes higher. Read about bubbles in the oil somewhere, perhaps it's contributing to the weird harmonics and your declining mental state, I hope it's not affecting mine too. We don't really do class action suits over here. ;-)

Andoiwebb

Interesting read and I can completely understand it driving you mad, as I have the same noise and it's annoying. It's clearly a 'characteristic' (FAULT) of the d4 and there doesn't seem to be a cure, I'm going to try attaching some dynamat type material to the struts and the arms to see if this absorbs the resonance. I realise that it will come unstuck, probably fairly quickly, but it's marring my enjoyment of an otherwise refined car. I do 50k miles a year in the UK and it's getting on my nerves!

KnappAttack

I have been following this thread since before I purchased my A8. I had driven a base A8 with the 19's on it and thought the vehicle to be quite loud with tire noise. It was not equipped with dual pane glass however. After that drive in the base A8 being very underwhelming, I decided to purchase a BMW 550I X-Drive loaded with everything, the BMW was sooooo quiet and good riding with the M-Sport package and adaptive suspension package w/active stabilization. Well, after a bit of trouble with the BMW, and encouragement from the dealer to go away from the BMW and go back to Audi, I decided to go back and try a sport package A8 loaded with everything, including dual pane glass and 20's on it. What a world of difference! I eventually found my CPO'd Sport Package D4 out of state and had it shipped here. Even though it has 20's on it, it is much quieter than the base model I tried with 19's on it, I will say it was one thing that made me go try a BMW in the first place, the base A8 with 19's was quite loud and annoying. I'm not sure why mine is whisper quiet other than the dual pane glass, I would think the shock package should be the same between the vehicle I drove this spring and my car, and according to the reports here, my 20's should be louder than the 19's. So the only difference I see is the sports package and the dual pane glass. Well also the difference in tire size and brands. The Base A8 as I recall had 19" ContiProContacts on which were very quiet on my A6 however.

My vehicle has 265/40/20 ContiSportContact 3 summer tires on it. I'm switching to wider 275/40/20 GoodYear Sport All Seasons next week and we'll see if they are any different, but they are also supposed to be very quiet according to the reports on Tire Rack.

How many complaining of this noise have dual pane glass and/or the sports package?

Andoiwebb

It's definitely nothing to do with the glass, all UK A8s come with that as standard. The noise is from the bulkhead area.

Baloo588

I had high frequency vibration buzzing and humming after the bad winter in Feb2014 and I had to go back and forth 4 times to the dealer on my 2012 Audi A8L for the problem. They rulled out the wheels and tires and looked into the driveshaft. They rotated it 180 degrees which didnt help with the vibration. They finally got a tech from germany to look at the car and they ordered a new driveshaft which solved my vibration/humming feel on the A8L. It had about 51k miles at the time.

needles

There has to be something in common with those who have the noise and those who don't. I do not have the dual-pane glass in my A8L and I absolutely do not hear this sound running factory 20's and the OEM Pirelli summer shoes.

Someone should start a Google Doc spreadsheet to capture A8(L), year, wheel size, tire size, etc.

Bladerunner

I've always had the UK 2011 factory fit tyres
PIRELLI 255/45R19Y P ZERO AO XL
255/45 R19 104 Y

Has anyone tried the 2015 Contisilents?
http://www.continental-tyres.co.uk/www/tyres_uk_en/themes/press_services/hidden/020813_ContiSilent_en.html

I'm due to change all four at £870, how much extra would ContiSilents cost?

9dB per tyre?

Thanks in advance!