Sounded like an M-80 went off when it hit the car. Thankfully it was fully contained to the windshield and no other damage on the car. Very thankful my daughter had decided not to accompany me on the trip cross-country or she would have had a face full of glass fragments from the inner layer of the windshield. The membrane in the windshield's center layer kept the rest intact.

 

So there are consistent complaints or at least comments on this forum about road noise in E63's. I'm sure the suspensions and primarily the tires are to blame, so not much can be done there aside from finding slightly quieter tires when it comes time to replace...

However, I've also heard comments that some significant noise comes from road debris/pebbles/etc hitting the wheel well liners (can't corroborate, as I don't pick up my wagon until tomorrow). Has anyone considered or tried spraying the wheel well liners with an acoustic treatment to try and deaden the sound? Seems like it would be a pretty easy DIY, but not sure how well it would work...

 

Unless you drive a lot on gravel roads, I can't imagine this doing anything. In 10,000 miles, I've never heard any noise from the wheel wells. 90% of the noise is tire noise. It's really not bad for a car of this sort. If you get an AMG, you need to know what you're getting into. Stiffer ride, more noise and replacing tires every 10K miles come with the territory.

 

Fair enough...wasn't sure how big a problem it is/was...

 

I have been thinking about this very thing for a while now. As you mentioned, a lot is from the low profile tires with stiff sidewalls. Obviously, this transmits road noise. Also, I think these cars have fairly firm suspension bushings (better handling) which also transmit more noise. But I do think the fender liners are also a significant source of road noise because of the material they are made of. They are a very hard composite plastic and just tapping them with your fingernails will illustrate how hard the material is. Even if you aren't driving over a bit of loose pebbles on the road, I believe driving on a rough road causes these rock hard fender liners to resonate and this sound goes right into the cabin.

At first, I was thinking of putting dyna mat on them but that would look terrible so I think I may try removing them and having them sprayed with bed liner because it's really durable yet a bit elastic. I think this elasticity will create sound dampening and reduce the fender liners from resonating. I just haven't got around to actually doing this but I think I will eventually. The amount of noise will vary widely based on the roads everyone drives on. On smooth roads, the road noise is very low and the cabin is much quieter than the average car. On rough/coarse roads, holy hell is it loud. LOL

 

Adding sound deadener in the wheel wells can make a difference. Adding it to the liners can be problematical. I have a Corvette. In one aspect the Corvette is similar to the AMG - it has wide tires that function really well in transferring noise to the vehicle structure. I was not able to add any deadener to the liners as they were a pressed fiber and I couldn't glue the deadener to them reliably. I did apply deadener to the wheel side of the wheel well metal (liners removed, rear only) and it did reduce noise a noticeable amount. How much it will help on a AMG depends on several factors - can it be applied reliably to the liners (side opposite from the tire)? Can it be applied to a significant portion of the metal? How much deadener/padding is on the wheel well in the interior? It really functions as a package with each part doing a small part. To complicate it more, the sound isn't a single frequency. Deadeners affect higher frequency noise. If you're older or a "turn it up" junkie your higher frequency hearing will be compromised and lowering high frequency noise isn't much help if you already hear very little of it. Beyond that, adding deadeners and sound blockers in the interior can have a significant overall impact. I did this on my Corvette. Stock it is a very noisy car, way noisier than a E series. After I did the project the first comment my wife made was it was quieter than her Lexus RC350. It isn't as quiet as the E63S, but it isn't that much noisier.

 

Have you been in Europe? Some roads are good but a lot of roads are in bad condition also.


Not very strange, ACP is not the correct name of the option. It's really named PAF

 

My E450 is pretty quiet and comfortable.