gainful

Have acoustic glass installed and did a sound test:

Idel: 37db
60mph on smooth asphalt: 57db
60mph on rough pavement: 60db
25mph and acceleration at 3k rpm: 45db

These numbers are not bad for an SUV but still not at Lexus ES350 levels.

BCRCornet

+1

Skizz

My '43 is still on the boat, scheduled for delivery at Baltimore port on Friday. Got my VIN and pulled the option codes. I have a code 840 (privacy glass) but no 851. Called my SA, told him what I found out about the car not having 851 and gave him bulletin number. Although I have to take delivery first and then open a complaint, the materials according to the tsb have been ordered and will be waiting for install when I take it back in to open the complaint. The build date was Feb 9.

Just seems odd the random nature of it; whether a car has the acoustic glass or not. In US, it is not on the order sheet online, nor on the DOG, as I sat with my salesman while we spec'd the order from beginning to end, line by line. I pretty much got every option except exterior carbon fiber stuff, heated rear seats/steering wheel and HUD. I have the P3 package and even the designo black interior. So I don't think it's a package issue, at least not in the US with the '43. Go figure.


So, anyway, whether the acoustic glass is a big deal or not, thanks forum members for shining a light on this.

MercedesTheBest

i have the acoustic glass on the drivers and passengers front windows, but my windshield doesn't say it is acoustic. does anyone's windshield say that? and what about anyone with the head-up display?

BCRCornet

My driver's and passenger's front windows do have "acoustic glass" marked on the logo.

I had my windshield replaced three weeks after taking delivery because of stone chip damage (thanks, I-5 in Washington state!). I neglected to check the original windshield for an "acoustic glass" marking before it was replaced. However, the replacement windshield was ordered through the local M-B dealership's parts department by supplying my car's VIN, which the dealer cross-referenced to get the replacement windshield's part number.

After installation, I could not find any "acoustic glass" marking on the new windshield. Now I don't know whether the original windshield and the replacement windshield are different, or the same.

In the dealership's showroom, I checked the windshield on a GLC, and it did indeed have "acoustic glass" marked on it.

Back to the parts desk - I asked the parts guy to look up the part number for my VIN, and it matched the replacement windshield I got. He assured me that was the proper, and only, replacement part for that VIN. One possible conclusion is that an "acoustic glass" replacement windshield is not available, at least, in Canada. Or maybe - the replacement windshield is "acoustic glass", but lacks the marking.

I asked the parts guy to look up the replacement part number for the GLC in the showroom with the "acoustic glass" windshield (using that car's VIN). The replacement part is the same as the one I got for my car.

Oh, well.

Daniel BG

It is very easy to see if you have acoustic glass...

(can't get the page to load up... but found the picture in google)

BCRCornet

Thanks for the tip - the photo applies to the side window glass. My problem is the windshield: any suggestions on how I can tell if the windshield is acoustic glass if it doesn't say so on the logo?

Daniel BG

I may be wrong... but never heard about the windshield being acoustic nor an option for that.... When I ordered mine they told me that the front side windows were acoustic...

gainful

Just a reminder guys -- Altho the acoustic windshield may help reduce the noise, i found it is less strength than regular glass.

My windshield had the weird "twin chips" -- meaning there are 3 places where there are two chips about 3 mm apart, what looks like caused by 1 stone hit.

All things have goods and bads. Even if you got all front windows and windshield replaced with acoustic glass, the car still has fair amount of noise in it. - To me, the insulation in doors is not as good as GLK. Also the run-flat tires are big source.

So if you really want a quiet car, don't pay attention to acoustic glass -- go get the tires replaced with regular tires.

BCRCornet

(Please click on the thumbnails below to see the fullsize image.)

This is the logo on my replacement windshield.

This is the logo on the windshield of the GLC in the dealer's showroom.

Maybe only windshields installed at the factory are marked with the "acoustic glass" logo, and replacement windshields lack the logo, but are nevertheless "acoustic glass" anyway?

dieseldoc

Cars with HUD have acoustic Windshields.

Widman

Just received my GLC 43 AMG last week. The front windshield has acoustic glass
(I have the HUD), but the side windows do not have acoustic.

Lee Wireless

My 43 does not have HUD, but does have an Acoustic Windshield.

Lee Wireless

I wouldn't bet on it.

dieseldoc

I have acoustic side windows, but my windshield is not marked acoustic. I do not have HUD.

guido3

My understanding is that HUD (code 463) is always automatically bundled with the acoustic windshield; however, acoustic side windows are not included unless "acoustic glazing" (code 851) is also on the build order.

Supposedly, code 851 includes both acoustic windshield and side windows. The absence of acoustic labeling on some windshields certainly confuses things, but that doesn't necessarily mean these windshields are not acoustic. Of course, we can't be assured that the code requirements are always uniformly applied during assembly. Glass supplies on hand probably dictate to some extent which type of glass gets installed. Considering code 251 is/was a no-cost option in the U.S. -- with no buyer input possible -- I suppose that gives/gave M-B some freedom to keep the assembly lines moving. Strictly my opinion.

Skizz

The thing that gets confusing is that, at least in the US market, option code 851 (for acoustic glass or glazing) is not an orderable option. In other words, there is no box to check for it like there is, say, the HUD option or heated/ventilated seats. As I was ordering mine, I was aware of this issue and looked for it with my dealer while we were placing the order. It just wasn't there as an option. So, what happens? Mine does not have it on the build sheet, even though I have damn near every other orderable option. So, I had my contact at the dealer pre-order the 851 front side glass as stipulated in the TSB so it will be there when I open a noise complaint, also as stipulated in the TSB. I'm sure, however, that I won't have the acoustic windshield glass.


Ultimately it is probably not a huge deal. I just find the screwiness and random nature of it irksome, even if it is a supply issue. MB should own it and have factual information on it at the dealer level, IMHO. Generally speaking, the dealer has no idea what this is all about.

Philamg

In the UK my build sheet shows "heat insulating glass", is this the same or different?.

gainful

Guys, don't fuss over acoustic glass....it has minimum help on reducing the noise...if you really want it quiet, go get a set of non-runflat tires.

guido3

Yes, same glass.

Philamg

Thanks Guido3

dieseldoc

Looks like same exact windshield except not marked acoustic glass. I bet they are the same.

BobbyT

gainful,

Do you have comparable sound test data for the Lexus? I'd like to take a look at that.

Here is a test of the GLC:

Richard

Current EPCnet shows no different windscreens for option code 851 on either GLC coupe or full-size. I have a UK (RHD) GLC full-size (what is the terminology) with HUD but windscreen is not marked Acoustic. My side windows have been changed to Acoustic. The HUD windscreen is not different between LHD and RHD cars according to EPCnet either.

Richard

Philamg

Windscreeen on my GLC43 delivered last week is marked accoustic same as all the other windows.RHD UK car.