Loud tyre/road noise

[Chris1947@]

This is my first post. My name is Chris.

I own a 2012, W204, C180 saloon. I can’t get used to the extreme road/tyre noise. The car is fitted with 18” alloys with low profile tyres which I believe are contributing to the level of the road noise.

Could anyone please tell me if this marque of car can have 16” alloys fitted with deeper profile tyres that ought to dissipate the road noise.

Thanks,

Chris.

 

[Blobcat]

Hello and welcome

I expect 16” wheels will be an option, check your drivers manual and inside the fuel filler cap as that should list all the original options.

 

[LostKiwi]

It's more likely a function of tyres fitted. Some tyres are notoriously noisy.
What's it running?

 

[Chris1947@]

Thanks for your reply.
I have owned the car for approx 12 months. When I bought it there were very cheap Chinese tyres fitted. I assumed they were responsible for the noise. I had good quality Dunlop tyres fitted about two months ago after discussing the problem with Mr. Tyre. They are rated at 78 decibels which I believe is a low as you can get. Still the same irritating noise. I have had the alloys redressed and the tracking set up accurately. Unless you feel that Dunlop tyres are inherent noisy I woul still like to know the answer to my original question.

Thanks,

Chris.

 

[LostKiwi]

Do you mean 68db?
If it's 78db they'd be very loud....

Also what's the load rating? It'll be something like 95, 98, 103 etc.

Finally what pressure are you running them at?

 

[Gazwould]

You could always add more sound insulation.

 

[Chris1947@]

The tyres are 225/40R18 (92Y) Dunlop SPMAXX RT2 XL tyres. Sorry, noise rating is 71

 

[Droverunner]

Wife's CLK runs those exact same tyres in 255/35 18 rear and 225/40 18 front. They are not noisy.

 

[Chris1947@]

A decimal meter in the car register 85/90 decibels at 50 mph. What else could it be?

 

[Droverunner]

What car are you comparing it to?

 

[Chris1947@]

I was a rep for over thirty years and have driven many different models. None have made this noise. I am very close to selling the car.

 

[Droverunner]

It's odd as they are normally thought of as a refined car.

 

[LostKiwi]

If its a 'Sport' spec or AMG line it may have oversize brakes and calipers meaning 17" will be your limit.

One thing to try - at 50 drop it into neutral and see what the noise level is. That will confirm if it's road noise or something else.

 

[Chris1947@]

The car is absolutely superb other than the irritating road noise. I have spoken at length to the Dunlop tyre technicians as well as the mechanics at my local Mercedes branch. Nobody can explain the cause other than low profile tyres are noisier than higher profile type. Hence the original question; can I fit 16” alloys just to see if it makes any difference?

 

[Chris1947@]

It is not a sport or AMG spec. It just happens to have AMG alloys. I will try what you suggest. Thanks.

 

[Droverunner]

>>>at 50 drop it into neutral and see what the noise level is.

Yes a worthwhile proving step. A slight downhill on a quiet bit of road is useful to give you a few seconds maintaining speed while you think about the difference if any its made. Also gently move the steering from side to side and see if that causes any change.

A long shot is any replacement suspension arms/joints not to OE standard or not correctly pre-loaded.

 

[Gazwould]

If its a 'Sport' spec or AMG line it may have oversize brakes and calipers meaning 17" will be your limit.

One thing to try - at 50 drop it into neutral and see what the noise level is. That will confirm if it's road noise or something else.

I wish , in that trim it's 295mm and 300mm rear , yet a smaller and lighter SLK gets 344mm fronts , what were they thinking !

 

[BreadvanMatt2022]

It is not a sport or AMG spec. It just happens to have AMG alloys. I will try what you suggest. Thanks.

Hi Chris, Did you ever get a solution to this Tyre / Road noise problem?

 

[mioba]

The OP has not logged in for a while. Guess he got tired

 

[BreadvanMatt2022]

The OP has not logged in for a while. Guess he got tired

;-) Thanks for letting me know. Not to worry.