Jaywalker

I'm selling my 2008 VW Rabbit this week and am considering a C250. Can you comment on the road noise, please?

ggms16

My C300 is quiet on the road.. A lot, but sometimes the wind noise can be irritating at high speeds.

Sportstick

Some helpful reading. I don't know if any other changes have been made since our older cars were produced.

https://mbworld.org/forums/c-class-w...d-you-use.html

Glyn M Ruck

In 2010 production Benz fitted a modified sound deadning kit. I have no idea of starting VIN.

Sportstick

Did they go after the plastic spare tire well? That seemed to be the focal point of sound amplification from my assessment.

CD30043

Opinions--would one of those rubber cargo liners that just sit on top of the carpet provide some sound deadening value as well?

kev10

I use a Weathertech DigitalFit cargo liner in my '12 C300 and I didn't notice a material difference on noise. The car is already quite quiet.

I just came back from an one-week Yellowstone trip renting an Infiniti G37x. It was a very impressive car, but I like my C300 better. Regarding comfort and looks, C300 receives clear votes from my family, especially from my kids. C300 has a slightly larger interior and softer suspensions, and it runs a bit smoother and quieter. I also think C300 doesn't lose ground on the handling against G37x. The only thing that G37x does better is being faster and powerful, but that is not a factor for a non-aggressive driver like me.

C300CA

Exactly. I had a few times G35 as a loaner when my QX4 was in service, and found the same.
I made a year 2011 comparison table out of Consumer Guide (Auto) including C300, 3-Series, Volvo, Lexus, Audi, etc., of the same category. C300 has a highest total score. Quietness level is also the highest. I already made decision on C300 but just wanted to double check if there was anything else I need to know to make last minute change.

I want to make it a bit quieter but evey time I think about it I said forget it.

kevink2

For minimal road noise, in most cases it's very important to rotate tires and reverse the direction of rotation on the car (directional tires excluded). This should be done with every oil change, or sooner. That's why some have complained about road noise with the W204.

For ultra quiet, the aftermarket kits mentioned will definetly help.

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CD30043

Not to open a can of worms, but do any of you ask the dealer to hand torque the lugs or just leave them to their own devices?

RLE

I know from my own observation that my dealer uses a torque wrench for the final tightening although they may spin the bolts on to that point.

Where you have to instruct them is the ordinary tire store who mount wheels on F-150s all day where it doesn't matter.

But I wouldn't allow ordinary tire shop emplyess to mess with my wheels anyway. I recently replaced my C300's tires and I let the dealer mount them (drop shipped from Tire Rack) because I knew they would not damage them. And if they did would make it right. BTDT.

RLE

The majority of the road noise comes from the tires. And when you install a set of truly quiet tires you will see how true that is.

kevink2

If by "spin the bolts on to that point" you mean the final torque spec, then I have an issue.

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rb23lb

what happens if the bolts are torqued wrong? how does this cause more road noise?

Jaywalker

Thanks for the thoughts. I test drove one today over some pretty noisy roads and it seemed pretty quiet to me. It was definitely quieter than the same ride in my VW. The C250 is in the hunt for a buy.

Hadn't thought about rotation of tires as a component of road noise, so thanks for that, too.

RLE

The only "issue" here is that you didn't read my post carefully enough. The first sentence dealt with torqueing the bolts. Spinning the bolts means with the impact wrench but not seating them and I thought that was obvious..

"I know from my own observation that my dealer uses a torque wrench for the final tightening although they may spin the bolts on to that point."


That's what I do with my 28V Milwaukee cordless impact wrench and it saves time and effort. Different deep socket, also.

kevink2

---> IGNORE THIS POST !! <---I thought I was replying to RLE, and not rb23lb.


I was responding to you who had replied to this off topic question:

"Not to open a can of worms, but do any of you ask the dealer to hand torque the lugs or just leave them to their own devices? "

obviously

---> IGNORE THIS POST !! <---

I thought I was replying to RLE, and not rb23lb. Thanks to RLE for pointing this out..

.

kevink2

My "issue" was conditional, as I stated:

If by "spin the bolts on to that point" you mean the final torque spec, then I have an issue.

IMHO the statement was a bit ambiguous as "that point" could be taken more than one way. You could have replied "golly gee KevinK2, they do the final torque-to-spec by hand with some additional bolt rotation."

I did read your post carefully, perhaps too literally.

I am cautious about shops that advertise hand-torqueing, based on what I witnessed:

I have seen shops that record your torque spec on the invoice, and advertise that they hand torque the bolts. I then watched them overtorque the bolts with the impact wrench, obvious by the lack of relative motion between the socket/bolt and the wheel when they were torqued. I saw this through a customer window to the shop. I was having race tires (Kuhmo V700) mounted on wheels I brought in .. I did the final install and torquing.

Bottom line, sorry for the confusion.

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RLE

But the "spin the bolts" comment was mine, not the person you are now addressing. Hard to keep up sometimes, isn't it?

Glyn M Ruck

Guys - This is a road noise thread - can we stay on topic please.

Glyn M Ruck

To my knowledge ~ No.

Tyres have much to do with noise & stopping them from cupping & feathering which creates air pumping noise by changing rotation is a big help.

Known noisy tyres on this chassis are the Conti Sport Contact range.

Known quiet tyres are some of the Bridgestones, the Michelin PS2 & Exalto PE2 & the Yokohama AVS db2.

C300CA

tirerack.com has all tire rating including the noise level. I am not sure if that is a good source of info. Once I bought a set of Michelin tires with much higher quietness level than factory eqipped Bridgestone for my SUV, based on tirerack, and found they are pretty much the same.

Glyn M Ruck

Unfortunately tyre noise transmission & it's harmonics is chassis dependent. Tirerack is a guide but not necessarily a good one for some vehicles.

Sportstick

Part of the limitation of tirerack.com is whether one is looking at surveys or the test data. The test data is the result of their consistent jury of experts who are trained on their assessment scale and provide a higher level of inter-rater reliability. The surveys are comprised of sub-populations of buyers attracted to each category of tire, and who have their own set of expectations, so variance is quite higher. For example, someone who rates the Michelin Super Sport as having excellent dry handling and someone who rates a random Grand Touring tire the same way are not having similar experiences!

Having said that, but not having examined current production, I would still think about attacking the spare tire well first if it is still an unlined plastic tub.

kevink2

Yes it tiz. After a re-read, "that point" clearly points to the "final tightening" step. As Anita Baker sang, I apologise.

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Feathering Wear

Feathering wear has become more of an issue as the tire spec's have changed for new cars. 205-55-16 tires used to be a common spec for Mercedes, Audi, and BMW. Tires/wheels have changed to:

lower aspect ratio tires
wider wheels/tires
larger dia wheels

So recently, 225-45-17 has generally become a base level size.

These newer tires are more sensitive to alignment for even wear, and to avoid accelerated feathering, primarily on the front outer contact edges.

To check for feathering wear, place your hand over the tire and with light fingertip touch, move hand forward and backward over the top of the tire.

The actual feathering wear leaves the tread blocks with a subtle saw tooth profile, looking from the side.

If the tire feels rough on the back stroke of the hand, and smooth on the forward stroke, that indicates feathering wear, that makes most tires noisy.

Another sign of feathering can be seen when the tire leaves a print on a smooth contact surface, either by water or dusty dirt on the tread. Rather than showing nice, perhaps square prints, you only see the trailing ( or leading ) side of the block.

The feathering wear process is based how the tire tread blocks first hit the pavement. So by reversing the direction of rotation, when rotating non-directional tires, you also reverse the feathering wear process. To be on the safe side, I suggest this type of tire rotation with each oil change.

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