raja777m

used the below coupon and got the noico 80mil 36sqft black version for around 54$.
https://slickdeals.net/f/11790703-eb...src=SiteSearch

Alandf

FWIW--I think the biggest contributor to road noise are your choice of tires . I am running Continental Conti-Pro 245/40 R18 on the front and 265/35R-18 on the rear, NOT run flats and the car is really quiet. For comparison my previous ride a BMW 535 with runflats was the noisiest vehicle I've owned.

raja777m

Finally did it.
More pics and videos coming up.
Before:




After. I rest some left over pieces on top of the tire well. Will put some more without sticking on the top.

raja777m

Under the rear seat bench.

You see that hook next to the red wire, that one was tough by the way I pulled the seat from the other side.




After the deadening materials: I was lazy to stick them even..!

raja777m

Before:

Trunk only:

Trunk and seat:

After all the effort I feel I saved only 1-2 decibels.

And one more problem is, my tires are 17" stock Luxury wheels with Run Flat tires. They have enough tread to replace them soon enough.

thefisch

At least you took some measurements. Were those readings while driving over the same roads? The peaks and maxes seem lower.

raja777m

Yes, same roads, same driving style, same air pressure.

thefisch

Any difference to your ear?

raja777m

lol, no; only placebo effect in my brain that didn't effect my wife's brain.

thefisch

Oh well. Hope she didn't tease you about it.

drdantheman1

What app and what iphone do you have? I used "decibel sound meter" on my iphone X and recorded my measurements at: 68-70db going 75-80mph on concrete freeway. 66-68db going 75-80mph on newer concrete freeway, and 64db going 75-80mph on smooth black asphalt freeway.

I used noico sound mat around my adblue tank in the truck (although not sealed edge to edge like I see in the pictures above), with some leftover uhaul packing blankets all around it and on top. I also used the noico sound mats under the back seat. I just bought a new 17" set of pirelli cinturato all season plus tires.

I still think my e250 is loud, but my previous car was a supercharged range rover sport with acoustic glass. I will say that it is definitely quieter than my wife's porsche cayenne with 21" wheels and conti dws tires.

raja777m

iPhone X with 'Decibel X' app (all Software are up to date, FWIW).
Even though I blame the run flats on my 17" but still I got minimal results.
Anyway, that's just my experience. For other people who are starting this mod/upgrade, make sure you take readings as such for educational purposes.

mellonc

DB levels have a something close to an exponential curve. Every 3 decibel increase is a double in sound volume. If you can decrease 1 to 2 decibels that would be a very good reduction in noise. Auto engineers give each other high fives when they lower DBs by 2 or 1.

oogurkan

Hello, sorry for my english..
I did an insulation upgarde for trunk area which resulted a noticable noise reduction for my sedan w212.
It is applicable for especially high/mid frequency tones which comes from rear side of car. Here are the photos:

My spare tire, tire kit and trunk covers. Removed before installation.

My tool bag and materials.

1st step installation of Insulation Material. "Oto Yalıtım 11". Made with polyester, self adhesive very strong, flexible. I noticed that the material is compact/intensive, 4mm thickness. Durable up to 110 Celcius. This is for high and mid freq tones.

You Tube

1st step installation of Insulation Material. "Firex Foam". Self adhesive very strong, flexible, fire resistant with 20mm thickness. This is for low freq tones.

cj_sharky

212 has its trunk insulated enough. You should start with the floor, from under the seats to the trunk. There is no need to insulate the spare tire, its door is good enough.