2018 C63s AMG Coupe not tracked:
15,000 miles and the front tires inside edges are down to the cord while the rest of the tire is about 50% left. The wear is a very narrow strip on the inside edge. The Mercedes service department says this is normal for this car. I disagree. This is a very dangerous situation as the front tire could fail. Not easy to see on the car unless your looking for it because the car sets so low and this edge area of the tire is hidden from view when not on a lift. Mercedes says its because of the powerful engine! I mentioned the car is rear wheel drive! I'm insisting they check the wheel alignment.

 

Normal.because of negative camber. You can get a kmac kit and make it flat but the car will understeer. But you'll have longer tire life.

 

Yes, you need your alignment checked. You will see more pronounced inner tire wear with the aggressive camber setting in the front, but excessive wear like this is generally caused by an incorrect toe setting. It causes the tires to scrub over the edge and wear down to the cord. I discovered the same issue on my 2019 C63CS at around 10k miles. Had it alignment and as suspected the front toe was out of spec on both sides. This is not my first car with aggressive front camber like this and I've only ever had excessive wear like this when the alignment was off. I had the same issue on my last car at one point and again the toe was off and properly aligning it fixed the issue. Don't even debate with Mercedes, just tell your SA to align the car.

 

15,000 miles is a lot for our cars and an average spirited driver.

 

Normal. I got 20K outta mine. Did alignment inspection at that point (friend owns a wheel/tire shop); it was within spec.

 

I'm waiting for my new tires to arrive (255/35/19 and 295/30/20 PS4Ss) before I go back to the Mercedes dealer to check the alignment accurately (accurately adjusted alignment = new tires installed.) Meanwhile the car is not driven because of the excessive front tire wear.

I plan to have the chamber and toe in adjusted to the lower acceptable range number to maximize tire life. What will the resulting handling characteristics be? My guess is less toe in = less high speed directional stability and quicker steering response, less camber = more oversteer? Is this right?

 

First off, camber can't be adjusted on these cars unless you get aftermarket adjustable control arms. Same for caster. The only thing that can be adjusted with the factory suspension is the toe. Toe out on an RWD can mitigate understeering and improve the handling.

 

Regarding alignments, what makes you think your cars are aligned correctly from the factory? You think they are? Take a look at my pic. It's the before and after measurements. Note that this is on a brand new 2018 Porsche Macan Turbo which I purchased. Also note that Momentum Porsche of Houston never completed a proper alignment the first time though. Had to bring it back a second time.

Now with a 2020 S coupe and reading this thread, I wonder if I should have the alignment checked on this one as well.

 

Sorry! Wrong pic!

 

I would definitely recommend to check the alignment after you put some miles on it. I waited too long till the first service. What many don't realize I think is that a new suspension settles over time. The alignment may be fine at the time the car rolls off the production line, but then as it sits and especially as it's being driven the suspension will settle over time and the alignment may be off afterwards. They do have tolerances and one can hope that the settling of the suspension doesn't push the alignment outside of the tolerances, but there is no guarantee.

 

Assuming T psi is not low, the wear you describe can be from camber or toe. Excess toe out will drag the inside tire edge and toe in will drag the outside tire edge. A road car will generally be set up with 1/8" toe in at rest. Camber is factory set but can be measured and changed by a pro. Toe is simple to reset.

Good luck.

 

I'm curious; did Porsche cover the alignment costs given it was delivered with improper alignment?

You can definitely have all sorts of quirks in a new vehicle that need addressing. But in my specific situation, 2 years and 22,000 miles later, my alignment specs were still dead on, and I had to replace all 4 tires (esp the front two) due to the cords starting to show on the inner aspects, with a lot of treat left on the rest of the tire. Aggressive suspension setting wear pattern. Par for the course. And the high end performance shop as well as the high end wheel & tire shop both told me this is typical wear they see due to Mercedes' aggressive factory suspension settings.

 

It can definitely happen even with proper alignment depending on the kind of driving you do. The purpose of the aggressive camber is so that when cornering hard the tire has an optimal contact patch and maximum grip and the tire wears more evenly. However, if you mostly drive in a straight line and rarely if ever corner even remotely hard or close to the limit, then you will most likely see this type of wear. It's aptly called camber wear. In areas that don't have many fun roads where you can fling these cars around corners I wouldn't be surprised if this type of wear is widespread. As I said previously, the C63 is not my first car with aggressive camber suspension setups, but I do regularly go for 200+ miles canyon loops and corner hard, so I don't see this type of wear, unless my alignment is off.

 

Describes my situation to a tee. Mine was my daily driver, and my daily drive consisted of essentially 70 miles a day of highway...

 

How to avoid excessive wear on inside edge...



No excess wear on inside edge

 

Never thought to pursue that. I was actually too pi$$ed. And, at that point, I just put them out of my mind and never looked back. I see them today as a learning experience.

 

YES, THERE IS ONLY FRONT AND REAR TOE (DIRECTIONAL) ADJUSTMENT OEM. New car industries best kept secret.

Gone are the days of precise front Camber and Caster along with rear Camber to allow to cater for other than showroom height conditions.

Day to day commuting encountering high cambered roads or altered height through load carrying or lowering. Fitting wide profile tires, wheels. Curb knock damage.

We saw the need therefore to "Fix it right the 1st. time" – to re instate full, precise / ongoing adjustment to resolve costly, premature edge tire wear.

By allowing to “adjust tire contact angles”. Essential to spread load more evenly (with excess edge load leading to ruptured side walls and rim damage).

Currently frustrated owners seeking a solution resort to going from one dealer or alignment shop to the next - or constantly changing tire brands In the belief that somehow, this could possibly alter the excess uneven wear.


For the C63/S – 2 Front kits manufactured:

1. #503316-2 J Simply replaces the upper arm/inner bushings providing precise adjustment – up to 1.5 degrees extra (Positive or Negative) Camber plus Caster adjustment. More than enough to resolve most tire wear issues.

This kit price is $395. Which compares favourably with cost of one single high performance tire. Owners pointing out KMAC Align kits have led to very significant cost savings.Extending out the need for “tire re-purchase” by a factor of 2 or even 3 times!

Specially designed so can be fitted without the need for upper wishbone removal or special tools.


2. #503316 K – This kit replaces the 4 major lower arm bushings providing same adjustment as above #503316-2 J Kit

Adjusting lower arms allows extra track width for performance/Race days, plus the 2 forward facing large diameter thrust arm (Caster adjustable) bushes are Mono ball/2 Axis. Deleting the OEM soft rubber, oil and air voided bushes thereby significantly improving brake and steering response.

These design bushes supersede steel spherical bearings which, with there wafer thin Teflon liners soon pound out. KMAC design having more than twice the impact, load bearing area.

Kit price $480

Camber bushes can be replaced without arm removal Caster arms require removal.


FOR THE REAR #502226 K

Replacement lower arm inner bushes. Precise single wrench adjustment of Camber. Up to 1.5 extra Pos. or Neg. (Plus extra Toe adjustment to compensate for the new rear Camber facility)

Kit price $480

No need for arm removal – bush extraction tool included.


Also for the Rear suspension:
#502628 K – This popular kit, replaces and upgrades the existing 6 rear multi – link arm bushings.

Significantly reducing rear end flex, twist, loss of traction. Especially when applying power to lane change/overtake

Kit price $480


Delivery Worldwide $40 one kit, $20 each extra.

PayPal, Visa or M/Card

 

Maybe a stupid question - what is the feedback you are hearing from customers who installed it and take the car for alignment to a MB dealer? Will they even touch it and if so know what to do if its not an OEM alignment feature? I need to bring my car for alignment to a MB dealer as it includes the Distronic, which an indy or any none authorized MB shop cant do.

 

I've had the K-Mac kit installed for over 10K miles now with no problems. My performance shop was able to do the allignment to factory specs and no distronic is not affected one bit.

 

Good to know but not really what I asked for.

 

When I discovered this wear I was surprised. I'm older, 69, and I still drive my cars to the edge of their performance potential. What I can't do anymore is crawl under my jacked up cars (especially with low ground clearance) checking the components for wear and tear, fluid leaks and such. (I miss this.) This tire wear was dangerous. I was going by what I could see from the outside that was 50% wear. Had a front tire blown during a pleasurable high speed drive, I wouldn't be writing this. Some owners who treat this car as a 'plug and play' experience can't recognize a dangerous situation such as this. My Porsche Macan Turbo with Pirelli all-season tires came with a sticker on the dash saying "warning do not exceed 150 mph with factory all season tires." Something like this should be done by Mercedes, perhaps "please examine the front tires frequently for uneven tire wear."

 

Thanks to this thread I checked the inner edge of my front tires and saw that the cords are starting to show through, despite the rest of the tire having plenty of life remaining. Ordered a set of PS4S in 275/35/19 and 305/30/19 yesterday and they arrived today. I'm not driving the car much these days due to working from home, but I am looking forward to getting these installed soon. I'm hoping they live up to the hype.

 

It's "dangerous" if you don't pay attention for it regularly. You don't need to jack up the car or get underneath the car. Turn the front wheels all the way to one side, and you'll be able to see the inner front on one side, and inner rear on the other. That's how my tire guy picked it up; as I was pulling up into the shop. And the rears, if you just put your head down, you can see the inner surface and see if it's wearing thin.
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Your profile says you have a coupe. I'd be interested to see if the 275s fit up front. I may have missed it, but I don't think I've read or heard of anyone fitting a 275 up front on the factory 19s. 265s, yes. So plz do post up your results and let us know if you get any rubbing.

 

quite a few ppl here with 275/305 setup so yeah it does fit on a coupe. that is what ill be getting too once these tires wear out in the next couple of months

 

In my research, I saw a couple people run the 275 front, 305 rear combo without issues. I'm at stock ride height so it should work with no problem. I'll report back or start a new thread once I have the tires installed. I currently have 265s on the front and there looks to be plenty of room for the 275s.