RE: Mercedes tyre 'skipping' - official statement

[Dave Hedgehog]

Cyb3rDud3 said:

A comfort issue, yes too right it is a comfort issue. It is bloody uncomfortable.

Driver side tyre is absolutely fine.

Just a comfort issue, year right.
They all do that? Yes right, just seriously think about coming to my home and take my car for a test drive as a potential buyer. Would you buy such an AMG vehicle?

I would walk a mile, but Mercedes say it is just fine...

what a surpise conti's

yours does look excessive, i would not be surprised if something else was a miss tbh

it would probably help to stop doing 200 laps on full lock whilst you film it

[super7]

MY E-Class Convertible does it with 19" wheels...... Assumed it was just one of front wheels loosing grip when on full lock.

[Bagpussawake]

A car definitely doesn't need to have big wheels and low profile tyres to do this.

My Lotus Excel has 205/55 x 15 tyres and does it all the time during low speed manoeuvres regardless of the weather but AFAIK Lotus didn't use Ackerman geometry for the Excel (I believe Lotus even knew a bit about combining ride quality with handling too )

[J4CKO]

Sometimes is this a collision of customer expectations and ideals with the realities of the mechanical stuff required to provide big power, huge traction and the expected look with the huge wheels and low profile tyres ?

[DanL]

As we're all saying "my car does / did this", I'll chip in too. My VX220 did this - it felt horrible! Haven't had a car before or since that has done it though, at least not one that I've noticed...

[kambites]

Bagpussawake said:

My Lotus Excel has 205/55 x 15 tyres and does it all the time during low speed manoeuvres regardless of the weather but AFAIK Lotus didn't use Ackerman geometry for the Excel (I believe Lotus even knew a bit about combining ride quality with handling too )

If they don't use Ackerman geometry, that'll be why it does it. The only way to completely avoid it is to use pure a pure Ackerman setup.

[R8Steve]

I'm struggling to see how this is all of a sudden an issue, even my S1 RS turbo did this and that was back in the 90's. (with car being from the 80's!)

Most cars i've had since have done it as well, some worse than others admittedly and normally the bigger/wider tyre the more noticeable it is.

Edited by R8Steve on Friday 27th January 14:29

[daltonr]

My R8 does this - they (+ many other performance cars) are well known for it.

[Sheepshanks]

R8Steve said:

I'm struggling to see how this is all of a sudden an issue, even my S1 RS turbo did this and that was back in the 90's!

Most cars i've had since have done it as well, some worse than others admittedly and normally the bigger/wider tyre the more noticeable it is.

It's destroying the tyres on some cars. Mercedes were taking cars back originally, but soon stopped doing that. Australian owners (RHD of course) are reporting the issue too, so it's not down to temperature.

[Krikkit]

R8Steve said:

I'm struggling to see how this is all of a sudden an issue, even my S1 RS turbo did this and that was back in the 90's. (with car being from the 80's!)

Most cars i've had since have done it as well, some worse than others admittedly and normally the bigger/wider tyre the more noticeable it is.

In some cases it leads to excessive tyre wear (unfortunate), but personally I think you've got people leasing fancier cars than they used to - it's not too hard to step up into a low profile tyred Mercedes these days, whereas your Mondeo from the 90s wouldn't do it...

[TorqueVR]

I've not read the thread right through but was interested in the juddery tyres. I had the same trouble on my Audi A5 and now on my 2016 Mustang. Both when the tyres were worn but still with some life left in them and both fixed by replacing the tyres.

[dvs_dave]

kambites said:

I don't think it's related to 4wd; it's just a steering geometry issue combined with very stiff tyre sidewalls.

The RWD models don't do it. Therefore it's not a geometry issue. It's clearly transmission wind up of the 4wd system. Whatever they're using for a center diff and it's lockup properties is the culprit.

[CS400]

Dave Hedgehog said:

its a combination of huge rims, cold tyres and tyres with really crap thin walls (conti)

just about every performance car i have driven over the last 10 years has done it incl the RS4 + R8, although not to the extent of the GLC video

my RS audi did it, replacing the conti's for MPSS's cured it instantly

my current merc does it and it will be getting a set of MPS4 S in due course (which have been reported on merc forums to cure it)

Thats interesting, I had MPSS on my Subarus and I have then on my focus RS and they all did/do it but only when cold and on full lock.
I never had the same problem when I had winter tyres on but I haven't bothered this year, so I have noticed it a bit more.

[optimal909]

Sheepshanks said:

It's destroying the tyres on some cars. Mercedes were taking cars back originally, but soon stopped doing that. Australian owners (RHD of course) are reporting the issue too, so it's not down to temperature.

Let John Cadogan know, I love his rants.

[Mr2Mike]

dvs_dave said:

The RWD models don't do it. Therefore it's not a geometry issue. It's clearly transmission wind up of the 4wd system. Whatever they're using for a center diff and it's lockup properties is the culprit.

Do you know for sure that the front suspension geometry for the 4WD cars is exactly the same as the 2WD? Seems unlikely to me.

[kambites]

dvs_dave said:

kambites said:

I don't think it's related to 4wd; it's just a steering geometry issue combined with very stiff tyre sidewalls.

The RWD models don't do it. Therefore it's not a geometry issue. It's clearly transmission wind up of the 4wd system. Whatever they're using for a center diff and it's lockup properties is the culprit.

Do the 2wd models run the same geometry, wheel sizes, tyres sizes, tyre makes/models, etc. as the 4wd ones?

If they're running exactly the same geometry on the 2wd cars as the 4wd ones, their chassis engineers deserve to be shot regardless of this problem.

[Roy m]

I think you've done massively well to get any form of response from Mercedes - they're usually not interested at all if a customer has a problem. Also worth considering that the Mercedes extended warranty 'doesn't cover existing conditions' so this 'non issue' is not covered by Mercedes no matter how bad it gets - total charlatans!

[ROLFSSEN]

My Alpina D3 and Boxster Spyder both do this, as did my M135i previously.

Slightly disconcerting when it first happens, but not a big problem.

[dvs_dave]

kambites said:

dvs_dave said:

kambites said:

I don't think it's related to 4wd; it's just a steering geometry issue combined with very stiff tyre sidewalls.

The RWD models don't do it. Therefore it's not a geometry issue. It's clearly transmission wind up of the 4wd system. Whatever they're using for a center diff and it's lockup properties is the culprit.

Do the 2wd models run the same geometry, wheel sizes, tyres sizes, tyre makes/models, etc. as the 4wd ones?

If they're running exactly the same geometry on the 2wd cars as the 4wd ones, their chassis engineers deserve to be shot regardless of this problem.

Minor differences to accommodate the front drive components, but not enough to cause this issue. Previous gen 4Matic's weren't known for this issue and it seems to coincide with the introduction of the latest 4Matic system, versions of which have the front drive disconnect feature and variable f/r torque split. Up until now, no 4Matic systems could do that. Such functionality is all down to the center diff/transfer case.

Find out what's being used for the center diff/transfer case and how it functions and you'll have your answer.

To me it seems like the usual 4Matic system with an open planetary type center diff, and a preloaded partial lockup clutch. Just this time they've upped the preload on the lockup clutch making the effect more pronounced and causing this low speed maneuverability issue.

[Cyb3rDud3]

Dave Hedgehog said:

what a surpise conti's

yours does look excessive, i would not be surprised if something else was a miss tbh

it would probably help to stop doing 200 laps on full lock whilst you film it

Mercedes does not offer a choice of tyres, surely they should supply tyres fit for purpose. Interestingly these are the only tyres that are MO marked for this vehicle.

Mercedes is unwilling to even look at it.

So to those who say this is normal; let me ask you this. Would you buy my car when it makes a racquet like that when you go around corners?
Further more can you please also explain why my Mercedes GL class doesn't do this?
Oh and why doesn't my Golf R do this...

Please don't make me list all the history of my cars. This feels like in the old mechanical 4x4 transmission like you are driving in high gearing on non-slippery surface and winding up the gearbox. Now anyone who has such experience knows that is not good for the car. Masking it or ignoring it isn't good.