cliffhanger7

my 2007 s550 has about 56k miles now. purchased it as certified used car with 37k miles and Michelin Pilot Sport A/S tires in mid thread life condition. it lasted only about 8 k miles. edges worn down. unfortunately I decided to replace them with the same tires.
the new set of Michelin pilot sport a/s has only about 10k miles but both inner and outer edges of all 4 tires are almost worn down. wear pattern is similar on all tires. same wear as the previous set.
I noticed that the wear areas on the edges are darker shade vs the center thread areas. looking at the tires with the car parked, these dark edges are not touching the pavement. I think this is from rubbing when cornering. I upped the tire pressure to 35 psi cold. did not help. the car has no alignment issues.
I am told that this is due to the car weight and cornering speed. so does it means that this tires were not designed for this car? or maybe use an XL load rated tires or ones with higher UTQG? I am now looking at replacement tires. appreciate any ones experience on tires for their S550 with 18" oem wheels. my own research shows Continental extreme conta ct dws 06 is my best bet followed by Kumho ECSTA LX platinum k and Goodyear Eagle F1 asymmetric a/s.

1bad540

get the car aligned, your not going feel the diiference if its outa whack!! bit yours def is. Pay the extra 100.00 and call it a day. Im contemplating selling my 19" non staggered amgs with new continentals if your interested and near Ny.

Mike5215

The tires were designed for the car. The car on AirMatic was not designed to handle well at the limits. The S may look the part somewhat depending on whether or not it has the AMG appearance package, but it's never going to be a great handler in the twisties, and pushing it will just chew up tires no matter what you put on there.

Unless you get an actual AMG car (S63/65) with the ABC suspension, or happen to get a base car that got the ABC as an option. Those cars stay flat in the corners. Spacers all around might help with wear around the outer edges and improve handling a bit. 20mm rear and 15mm front is as far as you can go on OEM offset rims without rolling any fenders.

I'd either toss it around less or plan on buying tires more often.

KNBS550

I concur with Mike. I chewed up my previous Yokohamas by driving hard through twisting mountain roads. That was the end of those tires. Driving a little less spirited now with Michelin Pilot A/S 3s.

SteveE400

If the wear you see is even (e.g. the same on the inner and outer edges of each tire, and all tires worn similarly), it is not likely to be anything to do with alignment or balance. Too much toe-in will wear one edge (outer) and too much toe-out will wear the other (inner) - not both. Camber and caster will be similar - a mis-alignment will cause wear on either the inner or outer edge of the tires, not both.


Your situation almost sounds like the tires are under-inflated. Under-inflation usually causes excess but even wear on the outside edges of tires, while over-inflation causes excess but even wear on the centers of the tread. I would look here first, as often shops will under-inflate tires on "luxury" cars to make them ride softer, even though their suspension is not designed for pillow-soft ride.

KNBS550

That brings up a good question. How many PSI's are you running your tires at?

mercedesbenzs55

I've had two sets of the michelin A/Ss, including the a/s3. This is an issue plaguing this tire. There's premature wear on one side of the tire, even with alignments. Michelin tried to fix this issue, but failed. I learned this from my best friend who worked in a Costco tire shop for 8 years, and is now q/a at Costco corp.

Mike5215

Cooper Zeon

(Mic drop)

cliffhanger7

Thank you all for the responses to my dilemma. The car was aligned 3 times two different shops just to confirm it is right to specification and tracts true. I like to emphasize that the wear is the same on all 4 tires.
Initially I inflated it to the recommended pressure of 29-30 psi. as I noticed the wear pattern which is the same on all tires and no sign of feathering, scuffing nor cupping, I decided that I need more pressure to increase the contact of the central thread area. Increased pressure to 34 psi. Still same result. Viewing the car tire when parked, I can see that the worn edges are not in contact with the ground surface. These edges are darker in color compared to the central tire thread area. So it is rubbing during turns as it deflects. As far as my driving habit, I do not push the car any harder on corners the same way I drive my 2005 Corolla, 2003 GMC Envoy, or 96 Impala SS. all these cars do not share the same tire wear pattern as the S550.
Having read all the comments, my inclination now is to try a set of tire with xl load rating, higher UTQG, and wider thread. So far the best candidates are: Continental Extreme Contact DWS 06 except tire width is even lesser than the Michelins now. Yokohama Avid Envigor or YK 580 meets all criteria with wider thread. Yokohama reviews not very good.
So, am I on the right tract in finding a solution to this tire issue or no matter what tire...

cliffhanger7

I believe you are right. I had another Mercedes, 1995 S420 with Continentals. I had no tire issue at all on that car. Drove it the same way.


I will try the Continental Extreme Contact DWS O6. I hope the higher UTQG, and XL load rating will help reduce this issue.

mercedesbenzs55

All four tires will wear the same because of an engineering issue of the tire, not your car.(lol)

Because of this issue you can get new tires for a discount from where you bought them. If the tire is still in warranty.

Nuru

That is what I am going to go too when I replace my OEM contipros

MrRat

30 or 34 psi is underinflation. The manufacturer plaque says 39psi on my S550. I keep 41 psi with no issues so far.

xpl0sive

where does it say 39 psi? mine says 35psi cold and add 4psi for warm tires.

jfz219

Below is a very good review of suspension design. Note the section on scrub distance. This is the distance between the the center of the tire contact patch and the pivot axis of the suspension. The greater the distance, the larger the toe-in and toe-out with breaking and acceleration. As power and performance increase, the scrub distance is reduced by design.

In this discussion, most static measurements are in spec: tire pressure, alignment, etc. Dynamic factors have not been addressed. Excess toe-in and out can be the result of tire spacers and soft bushings.

I would start with removal of any tire spacers and inspection of the suspension's soft components.


Suspension design: definitions and effects on vehicle behavior - Car Engineer
www.car-engineer.com › suspension-desi...

mercedesbenzs55

It's the tire design, not the suspension. If it were that then all tires would be wearing in this pattern.

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MrRat

I went out and checked. My car states 38 psi cold, +4 psi warm on the label by the gas door. My car came stock with 19s and is 4matic. I'm assuming the label must vary with options.

xpl0sive

ah strange. My car has 19's stock but RWD.

KNBS550

xpl0sive, does your car have a staggered setup with the 19's? If so, are the pressure the same on both front and rears? I'm wondering because mine came with 18's and I changed the wheels to staggered 19's. Been running at 34psi front and 38 psi rears.

KNBS550

xpl0sive

same pressure, front and back. front tires are 255, rear 275

cliffhanger7

UPDATED INFORMATION I just installed a set of Continental Extreme Contact DWS 06. Also had it aligned. A very small adjustment on the front right wheel was done. The right rear was at margin so adjusted also to set well within the spec. (I DID NOT SEE ANY SIGNIFICANT DIFFERENCE OF THIS ON THE TIRE WEAR). My cars tire pressure placard on the gas filler door says inflation pressures are:
front 29, rear 29: at max 100 mph
front 32, rear 33: at over 100 mph
Which is the same data on label on the driver door B pillar.
On the Michelins I put it at 35 psi which did not help.
The Continentals initially inflated at 30. I drew several white paint lines across the thread of each tire and drove it around to see the contact surface extent of all the tires. the edges were rubbing again. I increased the pressure until the contact patch do not extend to the tire edges. it turned out that the pressure should be at 37 psi minimum.
I will drive it several days to see how this set up works. Too early to make a conclusion. I was surprised that the ride on these Conti's are not as harsh as the Michelins at this pressure. Also it appears to roll/ride better. Just a perception, could be psychological.
Thanks again. By now several people I talked to agrees it's a tire issue, not a car issue. The Michelins were not up to the normal wear performance expected of the tires rating FOR THIS CAR.

xpl0sive

here's my tire pressure sticker from inside the gas cap. Car is a 2007 S550 with sport package

KNBS550

Thank you! I noticed my fuel economy has taken a hit since going to 19". Regardless, the car looks way better now than with the stock 18" wheels.