anb

Hey guys,

Thought I'd share this for those experiencing crabbing issues in their C43s.

As you can see in this video my C43 has been suffering some serious crabbing but I can happily say it's now 100% gone. You can see in the before and after

zibby43

How are you liking the new tires, generally? Has it brought out any noticeable/perceptible differences in steering turn-in feel, braking, grip, etc.?

Thought your comment about the reduction in noise was very interesting. What sorts of noises were you encountering with the RFTs (beyond the low-speed crabbing)?

Very nice channel, btw.

anb

Thanks mate,

I've done a good couple hundred miles now on the tyres and there is def quite a big difference in the overall feel driving. Steering is a lot smoother in comfort mode but still sharp in sport+. I'd say this is due to the softer non runflat. Same with ride quality, not drastic but it does feel smoother and softer.

Handing good so far, handles much better at low speed mostly due to the crabbing eliminated but feels about the same at high speeds as the pirelli's.

I do think road noise has been reduced a little aswell, this was something I noticed initally.

One other thing I noticed this morning was my mpg seemed better than normal but it may have been I was driving a little less sporty than normal but its possible mpg could be better but may just be because they are new and my old ones were very worn. Will def explore this though!

zibby43

Thanks for the info! The improvement in ride quality is a huge positive in and of itself. RFTs have come a long way since they first were made popular by BMW back around '07, but they're still no match for a traditional construction. Glad to hear about the other performance-oriented improvements as well.

A good set of shoes can really transform the car, and Michelin makes fantastic tires. If you end up doing a video review of the tires, please don't hesitate to share it.

Cosworth2000

Here is the thing. Run Flat sports tires are only to be used no less than 7 degrees above 0. Anything below that and the compound gets harder and less sticky since the run flats are summer tires that comes on the AMG models.

anb

Thanks! I'm def getting a review video of the tyres up soon. I don't post all my videos here because I don't want to spam the board but every now and then when I think something might be helpful to the community I share it here

TModelle

To the OP, your crabbing issue is certainly bizarre. I’ve never had this on my 2019. I’ve had all sorts of wheel/tire combos too. I have two other sets of wheels other than my original 19” set that came with the car. I wonder if other owners are having crabbing issues too.

stockbmw

Nothing on my 18 with non run flat winter tires. Haven't tried with original 19" conti5p in cold below 7C.

batman719

Nothing on my 2019 with OEM run-flats. And I'm here in Colorado; it gets plenty cold. I've since switched to non-RFTs for the improved ride and handling, but I never had crabbing like that even with the RFTs.

PFEAMG

One thing about the OPs car that may be an impact (not sure why) is his car has right hand steering.

Mr. J

RHD 4-matics seem to be more prone to crabbing than the LHD vehicles are. Possibly slight differences in the steering geometry. Crabbing is way more pronounced in the GLCs. On the GLC forum there are quite a few UK and AUS owners who have pretty severe crabbing issues.

My LHD cars are mostly fine. The C450 only does it at full steering lock while reversing. The GLC will do it a little at full lock in both forward and reverse gears but nothing as severe as the videos I've seen of RHD vehicles.

TModelle

That’s a weird one for sure. It’s the first I’ve heard of it. I’m RHD and I’ve driven a couple of C43’s from 2017 to 2019. Nothing ever close to any noise or crabbing during full lock even in reverse. I don’t think it a RHD thing. Maybe more of a temperature thing?

zibby43

My W204 C63 did it occasionally when I had my summer tires on and we'd get the occasional cold early fall night (50 F or below). When reversing.

David Hudak

i would say with a high degree of certainty it is temperature related. I am in the US and have a 20 C43 and experience crabbing in cold weather. exactly how the OP has described and shown on video. When its a warm day it does not happen. Near freezing or below i get it.

stockbmw

What runflat tires do you have?

David Hudak

Pirelli OEM 19" summer run flats.

///zhp04

Nothing unique to Mercedes. This is a long-discussed issue on the Porsche forums. Rather than trying to pontificate, I'll give everyone a couple of good links that address the issue.

https://rennlist.com/forums/991/9675...s-jumping.html

https://en.wikipedia.org/wiki/Ackerm...ering_geometry

superswiss

OP,
Let me first say that was some pretty bad crabbing, but as was stated above crabbing is not unusual. It's not just 4Matic cars, although AWD have more of an issue with it. Performance cars don't have perfect Ackerman geometry, because they prioritize high speed handling, which is better if the geometry is a bit off from the ideal Ackerman geometry. In AWD cars it's also a function of the center differential binding on a lock-to-lock turn. Now the second thing I wanted to mentioned, don't drive on summer tires when temps are freezing. The PS4 is actually relatively good even at freezing temps, but summer tires are meant for warm weather. I believe the stock RFT tires on the C43 are all-season, but you can order summer performance tires (order code R01).

Thirdly, the crabbing is most likely gonna come back as the tires wear. Not sure how many miles you had on your previous tires, but brand new tires have a lot more flex in the tread, because of the initial tread depth. As the tire wears, that flex goes away, and the crabbing will come back. Most likely not as bad as with the OEM RFT tires, but it will come back. The PS4 are great tires. I don't have experience with the 4, but I just recently put the 4S on my C63S and I had them on my previous RS5. They transformed my C63 much more than they transformed my RS5. Compared to the stock PSS the ride comfort is much improved, grip is amazing now, whereas before I had difficulty getting the power down. The 4S because of its construction and non-metallic belts just maintains a much better contact patch. I am curious why you went with the 4 not the 4S. I believe the 4S is improved, but it's also mainly for larger sizes. The 4 isn't made in larger sizes as far as I know. I'm not a 100% sure how the make up, compound etc. differs between the 4 and 4S, but there are some comparison videos between the 4 and 4S and as far as I remember the 4S is all around better in the wet and dry.

mo11

I switched to non runflats very early into having the car and don’t remember having crabbing issues on mine (‘17 LHD). Yesterday, I drove in heavy rain on the fwy here in L.A. when I decided to pass the truck in front of me. Before you know it I was hitting over 100mph changing lanes. I have the Ps4s and with the 4matic on c43, the car felt very surefooted. Even though the Ps4s is a summer tire, it felt very confident driving in the rain at that speed. I used to have dws06 on this car which were rated for wet/snow and have driven in similar situations... to be honest the ps4s’ handled a lot better even on wet conditions. I didn’t maintain the speed long enough, I just didn’t want to be behind the truck. Still, when I glanced at the speedo after that I was still at 85-90mph until my exit came up. I definitely don’t recommend driving at that speed, but I didn’t even realize I was going that fast in the rain. These tires get my vote.

EdC43AMG

as stated above, you can find this in many cars. Some more some less.

One of the factors it's the geometry of the suspension, it's camber etc... could affect. But mainly the tires it's a big factor.

for instance my Saab, when having a summer tires with 225/40/18 and when I had the 225/45/17, I noticed some crabbing in some surfaces and when the tires where in it's end of life and cold weather.

In the Merc, it's noticeable the camber position and the first thing I notice with the car VS other cars and mainly with my Saab 93 (I still have) it's how the Merc has a long steering radius, but far more direct steering. I've just noticed the crabbing 1 or two times, with really cold weather. I don't have runflat (I am lucky it didn't came with them from OEM), I have a dunlop sport maxx RT summer tires and to be honest I am not worried with it, as is not unusual in cars and in the conditions it happened to me in rough cement surface, where it's easy to have some slippage when steering it's forced and the car trying to steer.

gabemcclintock

Have a 2019 and live in Canada where it's really cold and have never heard anything like this on my 2019 or even my 2018. Thinking I'm lucky or this is definitely a right hand drive issue.

TModelle

I don’t think so, like you I have not heard anything like this on various C43 from 2017 to 2019, and I am in RHD country.

Chaznik

My 19 plate was identical, having new tyres put on today.

i always hated the drive on the Pirelli’s and the front are worn in less than 7000 miles

Mr. J

There are multiple threads about crabbing on this forum. Most of the complaints are from RHD GLC owners. There are also some complaints from E class owners. The issue seems to be much more common with the GLC than with any other models. It appears there are multiple factors involved including: wheel diameter, tire type, RHD/LHD steering geometry, front camber, and temp.

Early RHD GLC43s with 21" wheels appear to be the worst offenders. There are vids on this forum where you can clearly see and hear the front tires skipping. All of the worst examples were RHD GLCs. I have not seen nearly as many crabbing complaints about W205 C class as I've seen for the GLCs.

Chaznik

I had a Continental ContactSport 5 SSR MOE put on today and the car feels so much nicer than it did from the factory with the Pirelli’s on.

Also the rear tyre has a nice lip so gives it a wider stance too.

Well worth the £850!!