While out running errands yesterday I had a low tire pressure alarm pop up for the left rear tire as I was leaving an appointment. Pressure had been fine at 41 PSI going in, alarm was showing 18 PSI. So I quickly pulled into the next parking lot and checked the tire and didn't see any obvious screws or nails from my casual inspection. Grabbed the tire inflator from the trunk and pumped the tire back to something a bit north of 41 PSI then disconnected and headed to the nearby Discount Tire store to see if they could patch the leak.

The guy came out and had a look at the tire and told me it needed to be replaced. He showed me a photo from under the car of the inside edge of the left rear tire and the chords were showing along with an obvious split along the whole tire on the inner edge. Took a photo of the right rear and it was in the same state but just not leaking yet.

I was really surprised because I look at the tires regularly as I'm walking around the car and from behind and had even reached in and felt the tread depth not that long ago. But I'd never really bent over and carefully looked at the inner edges of the tire so didn't notice the higher rate of wear there.

Mercedes roadside care dispatched a flatbed tow truck to bring the car to the dealer and also gave me a complementary $100 credit for a Lyft ride home. The tow truck driver said this wear is really common on Mercedes, BMW, Audi, etc., performance cars because the rear tires are set up with a fair bit of camber as well as the fronts.

I didn't know this. The front tire camber situation has been fairly well covered and perhaps the rear camber mentioned too, but if so it didn't click and stick in my mind.

Replaced my original Pirelli tires at 9700 miles with the PS4S. I thought then that the rear still had life left in them but replaced them at the same time as the front tires to switch over to Michelin PS4S. As with this set I didn't really inspect the inner edge closely so don't know how much life they really had.

This set of rear tires have right at 18,000 miles on them.

This set had a higher percentage of time doing basic city driving and a few longer trips with only a handful of canyon runs. Nothing much to speak of for race starts or drift mode.

So, check your inner tire wear on the rears. Takes more than a casual bending over as I was doing and you've got to really have a good look.

On the bright side, I'm getting PS5S put on so will be able to report on that. Not replacing the front tires at the same time as I replaced those with a new set of PS4S not long ago. From the reviews the 5S uses a multi-compound construction that hopefully has a harder, longer wearing, material on the inner edge to extend the life given the camber setup.

 

Good practice going forward to check your tires once a year.

the negative cambers eat the e63/53 tires for breakfast.

 

The point was I had been checking them - at least from what was easily visible looking at the tire from the side and what you can see from the rear without bending way down to check the inner side.

I'd also recently had the car in for a B service for the first time at a non-dealer shop that specializes in Mercedes work. Their checklist didn't note any worry for the tire wear, so I'll have to have a word with them about that.

I'm sure my normal dealer would have flagged this as an issue had I brought it in to them for the service because I know the tire didn't suddenly wear that much in few months since I had it in, especially given I only drive the car about 4,000 miles a year typically.

 

Received photos from the service department.

I'm not sold on the camber explanation given what I'm seeing on the tread just to the inside of the damaged area on both tires. Still tread and the wear bar on the next section isn't even showing yet. The tire would have to be rolling practically on just the inner edge alone to wear just that portion down so bad.

Left Rear


Right Rear

 

Here was my front passenger side. All my front and rear tires had excessive wear to the point of steel belts were showing.

 

You should really think about replacing all four with PS S5's. The compounds are very different. I certainly wouldn't push the car with different grips on the two axles.

Even my wife remarked on how much quieter the car is. That droning on the highway is gone. The handling is crisper too. I can't imagine a more cost effective upgrade than spending another grand and have the S5's on all four corners. They also have an amazing 300 wear rating, so they're even a bit cheaper in the long run.

 

have the alignment measured so you know the camber.

Then get aftermarket rear camber adjustment kit - Either adjustable bar (moves top of tire in/out) or adjustable bushing (moves bottom tire in/out)

This tire eating non-adjustable rear camber issue is crazy but in Germany the gov requires way more thorough inspections then here in USA before you get an inspection sticker.
so maybe for them they like buying tires every 15k miles with tons of outer tread life left.

Just search "rear inner tire tread" on here and I bet you overload the search engine with threads.

Pure Nutz.

 

I’m still on my RFs and plan on switching up next chance. But funny thing is I’ve gone though replacing an entire set once already and it’s only because I had RFs that I was able to drive once the cords were showing. So for sure plan on being extra careful looking at the inner walls once I switch.

 

Prestige auto and owners presume there must be “precise single wrench / ongoing adjustment” - available for both Front Camber and Caster along with Rear Camber !

BUT THE REALITY - HAS BEEN DELETED. BECAUSE OF “EVER INCREASING SPEED OF NEW CAR ASSEMBLY LINES”. TO HAVE ADJUSTABILITY AND HAVING TO STOP / SET CAMBER IS NO LONGER AN OPTION !

NOW ONUS IS PUT BACK ON OWNERS TO FUND, COSTLY PREMATURE TIRE REPLACEMENT.

CAMBER IS NOW ONE ONLY SETTING - SET TO SUIT SHOWROOM HEIGHT CONDITIONS.

NO LONGER ABLE TO ADJUST TIRE CONTACT ANGLES - SPREAD LOAD MORE EVENLY. Excess edge load can also lead to high impact, ruptured side walls and subsequent rim damage.

WITH DAY TO DAY COMMUTING - Encountering excess passengers side edge wear through high cambered roads. Wheel squat / Camber change edge wear either one or both sides through extra passenger loads or lowering vehicle height. With no “ongoing” adjustment for curb knock damage. AMG models track days not being able to reduce understeer by dialing in extra Negative Camber.

WHILE ALL DEALERS CAN OFFER (to try and placate) - is that at factory height is within specs !

Leading owners / in frustration - going from one dealer or alignment shop to the next - or deciding must be a tire brand issue.

SEE SPOILER - TO FIX IT RIGHT THE 1ST TIME - RE TOTAL K-MAC RANGE MANUFACTURED.

FRONT & REAR DESIGNED - SO “BOLT-ON ADJUSTMENT” (No special tools or need for arm removal).




AUDI to VOLVO - K-MAC Experience Of Resolving OEM Suspension Shortcomings (and Costs) Since 1964 !

 

To be clear, my car is not lowered and runs at stock ride height.

I'm not complaining about the front camber in this post - it's been very well covered. My post is regarding excessive rear tire inner wear - apparently due to the rear wheels also being set with significant camber.

The front tire wear at least is more visible when the tires are turned one way or the other - the rear tire wear is hard to see unless you get down under the car.

PSA point being - check your rear tires more thoroughly every now and again so you don't get a surprise like I did. Lucky for me the tire decided to give up when/where it did and not on a trip with the family or out on the interstate far between exit ramps, etc. Tires won't be in now till after Labor day so four days without the car. Would have made a family vacation suck.

 

The better alignment shops have a alignment machine that will print out the alignment for all 4 wheels indicating actual values and whether they're within spec. My suggestion is find one of those shops and have them do a 4 wheel alignment. If there's a suspension issue that prevents a proper alignment it'll be obvious to them even before they give you the printout. It isn't free but it is cheaper than a set of tires.

 

Got the car back from the dealership with the new shoes. He's trying to get me the spec for the rear camber just to satisfy my curiosity, but said even the non AMG sedans do have higher wear in the inner side edges of the tires.

Hopefully the new PS5S tires will do better. He said there shouldn't be any issue with driving the car with the new PS5S rear tires and my half worn PS4S front tires. Not that long of a drive home from the dealership for me to get any kind of impression of the new tires and whether they are more quiet (one of the claimed improvements). Didn't notice anything weird about the car with the new tires and the mixed 4S/5S setup.

Here's a shot of the new rear tire for those interested.

 

With 4 of the 5s, the difference in noise is not subtle. It's really night and day. But keep in mind that the driver is sitting in a front wheel well, so I would imagine the bulk of it is attributable to the front tires.

 

that's refreshing.

usually when I try to get one or two tires swapped out (I understand one tire), but when two in the front or two in the back need to be swapped out, the tire person usually tells me and forecasts so much doom in my life like the differential will blow up, ill get into a crazy accident, My house will burn down, My business will collapse, The stock market will crash and so on and so forth. it's amazing how they know all this as a "tire guy"

so I just get all four replaced.

 

I'm skeptical of what people say about tire noise. All tires are quietest when they're new. So old noisy tires get replaced by new tires that are at their quietest. Are noise ratings by manufacturers done to a standard or just whatever the manufacturer wants to do to make their tire look better?

 

All I can say is, just wait until you try these. Even my wife remarked it sounds like a different car.

 

noise is one of the reasons I switched over to Continental from Michelin and it was a little better but not a world of difference. I have my doubts that different tires will make a huge difference in noise as they're just big & wide tires with lots of resistance . . .

 

I love all the doubters who've never ridden with four PS 5S's. Anybody else installed them and want to chime in? Everybody's entitled to an opinion, I guess.

 

ive used the same tire shop Most of my life and they talked me into replacing all 4 of my tires tomorrow. does anybody know if this is actually true?

they’d do whatever I wanted but said it wasn’t worth messing with.

have tread left on the rears, hate to throw them away. they’re mich alpin pa4’s that came on the car. Winters but like $400 a tire.

As for the fronts happy to see those crappy landsail tires go. (Think the car about bankrupted the previous owner)

 

if fronts and rears wore evenly over the life of the tires it would make sense to not stagger their replacement and get all four done everytime you get new tires

if the tread is in spec on the older rear tires I don't see why you can't just get two new ones up front

 

Great post on the lesser known rear tire inside shoulder wear. This occurs when the owner doesn't just **** away money replacing all four tires every single time the fronts wear out. Please immediately begin replacing all four tires every time, just like me and all the rest of us.

 

I just had an A service. My SA said they have installed a few sets of Pilot Sport 5 Ss on E63s and the feedback about reduced road noise is unanimous.