RE: Mercedes tyre 'skipping' - official statement
Discussion
havoc said:
Good reasons? Yes - budget, probably.
"No one could have designed it any better"? What about all those other mfrs of cars which don't exhibit such behaviour?
I'm quite happy to accept that this is a consequence of incomplete-Ackermann geometry and ultra-low / ultra-stiff sidewalls. But does it REALLY need to be there?
I've seen a number of (rather clever) suspension geometry innovations, from Honda's 'compliance pivot' which removes longitudinal deflection on hitting potholes/other road deformations, mechanical and electrical 4-wheel steer systems to artificially change the effective wheelbase, king-pin-inclination compensators, 'RevoKnuckle'/'PerfoHub' and other torque-steer reducing systems...and probably others I've forgotten about.
So I'm sure those ever-so-clever bods at Mercedes COULD do it better, most probably if they had the budget...which Merc clearly chose to spend elsewhere...
Fair enough. You're entitled to your opinion. But that's all it is, an opinion. As I've said, this behaviour is not especially abnormal. Plenty of cars exhibit the same, admittedly undesirable trait. I can only presume, through your rationale, that they all had inadequate development budgets or were designed by fools. I suppose it could be because not everything in life is black & white, but that would be just my opinion "No one could have designed it any better"? What about all those other mfrs of cars which don't exhibit such behaviour?
I'm quite happy to accept that this is a consequence of incomplete-Ackermann geometry and ultra-low / ultra-stiff sidewalls. But does it REALLY need to be there?
I've seen a number of (rather clever) suspension geometry innovations, from Honda's 'compliance pivot' which removes longitudinal deflection on hitting potholes/other road deformations, mechanical and electrical 4-wheel steer systems to artificially change the effective wheelbase, king-pin-inclination compensators, 'RevoKnuckle'/'PerfoHub' and other torque-steer reducing systems...and probably others I've forgotten about.
So I'm sure those ever-so-clever bods at Mercedes COULD do it better, most probably if they had the budget...which Merc clearly chose to spend elsewhere...
kambites said:
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.
The issue is apparently more severe on RHD cars. Almost non existent on the LHD versions, according to many owners. 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.
R8Steve said:
Cyb3rDud3 said:
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?
It would be game, set and match for me i'm afraid.
To add some seriousness, I drove my friends S4 yesterday and it was -2, it did something similar at full lock at very slow speeds.
eldar said:
The issue is apparently more severe on RHD cars. Almost non existent on the LHD versions, according to many owners.
That sounds like some of Donald Trump's "alternative facts" to me....My RHD Porsche does it. My LHD Corvette does it. Am I surprised? No. They are both high performance cars with wide tyres and excellent handling at autobahn speeds.
Cyb3rDud3 said:
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.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 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.
i will live with it till the tyres are shot and change brand
they are a 20" with only one conti tyre available but changing up from a 235 to 245 gives me a dozen options incl MPS4 S and will offer better rim protection, at a cost of a 1% rolling radius change (tyre wear is more than this)
Edited by Dave Hedgehog on Friday 27th January 17:03
Dr Interceptor said:
They don't do it when you go round corners.
They do when manoeuvring at very slow speed on full steering lock.
Have you got one? You sound like Mercedes, they keep on telling me when I experience this. Funny how I actually drive the vehicle and have a different experience.They do when manoeuvring at very slow speed on full steering lock.
Dave Hedgehog said:
would i buy one i buy a merc knowing they did this, yep i just did and it does
i will live with it till the tyres are shot and change brand
they are a 20" with only one conti tyre available but changing up from a 235 to 245 gives me a dozen options incl MPS4 S and will offer better rim protection, at a cost of 1% rolling radius change (tyre wear is more than this)
No they are not, they are 21" and only on MO marked tyre. i will live with it till the tyres are shot and change brand
they are a 20" with only one conti tyre available but changing up from a 235 to 245 gives me a dozen options incl MPS4 S and will offer better rim protection, at a cost of 1% rolling radius change (tyre wear is more than this)
All permanent awd (particularly performance orientated) cars will have a tendency at full lock to grumble a little due to slight transmission windup. It's part of the compromise between the optimal Ackerman geo and the awd system.
However the extent to which these 4matics are doing it is nowhere near normally acceptable levels, regardless of what the apologists are kidding themselves with. Thudding and obvious tyre skip is not anywhere close to how it should be performing, and is miles away from how Quattro's for example behave. As it doesn't appear to affect LHD versions, there is something going on with the implementation of the RHD 4Matic system. Be it a different transfer case/center diff arrangement, or bodged steering rack placement for RHD, or a combo of both. That's what needs digging into.
However the extent to which these 4matics are doing it is nowhere near normally acceptable levels, regardless of what the apologists are kidding themselves with. Thudding and obvious tyre skip is not anywhere close to how it should be performing, and is miles away from how Quattro's for example behave. As it doesn't appear to affect LHD versions, there is something going on with the implementation of the RHD 4Matic system. Be it a different transfer case/center diff arrangement, or bodged steering rack placement for RHD, or a combo of both. That's what needs digging into.
Edited by dvs_dave on Friday 27th January 17:07
Cyb3rDud3 said:
No they are not, they are 21" and only on MO marked tyre.
mine are a 20 and like wise have one MO tyre, but if you change the size slightly dozens of tyres are available its a conti and has zero tyre wall strength, they will be replaced with far superior tyres
Edited by Dave Hedgehog on Friday 27th January 17:07
Cyb3rDud3 said:
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....
The video looked pretty bad. Many of my cars have shown this trait to some extent and I've always assumed it's some compromise of Ackerman vs other factors (and 4 wheel drive performance cars generally been more pronounced than others). But none as bad as this.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....
If my car did what yours is doing in the video I'd be irritated, but a question. You are taking a full lock and accelerating on a most of those shots, I generally only crawl on a full lock (and am winding lock off as I accelerate). Are you doing it to highlight the problem? Or is that just a trait of some of the manoeuvres you have to make?
dvs_dave said:
All permanent awd (particularly performance orientated) cars will have a tendency at full lock to grumble a little due to slight transmission windup. It's part of the compromise between the optimal Ackerman geo and the awd system.
However the extent to which these 4matics are doing it is nowhere near normally acceptable levels, regardless of what anyone says. Thudding and obvious tyre skip is not anywhere close to how it should be performing, and is miles away from how Quattro's for example behave. As it doesn't appear to affect LHD versions, there is something going on with the implementation of the RHD 4Matic system. Be it a different transfer case/center diff arrangement, or bodged steering rack placement for RHD, or a combo of both. That's what needs digging into.
Totally agree with this, by BMW 335i does it just a little on full lock but some of the videos I have seen of the these new mercedes are totally unacceptable. However the extent to which these 4matics are doing it is nowhere near normally acceptable levels, regardless of what anyone says. Thudding and obvious tyre skip is not anywhere close to how it should be performing, and is miles away from how Quattro's for example behave. As it doesn't appear to affect LHD versions, there is something going on with the implementation of the RHD 4Matic system. Be it a different transfer case/center diff arrangement, or bodged steering rack placement for RHD, or a combo of both. That's what needs digging into.
you would be an idiot to buy one - especially considering you cant even adjust the geo fully (stupid morons at merc decide its not needed) and people need to have bolts welded on at their own cost.
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