Hi,

At around 49000 miles I had the tires of my 2008 C350 changed. Because that coincided with the time I needed to get "B3" service, I had the tires and alignment changed at the dealership.

The tires I ended up with were Michelin Pilots (my very poor decision, I guess) that the dealership filled with Nitrogen.

PART I - The Handling Problem
Here is my problem: When I took the car in for service, the handling was great (aside from the effect of the worn tires). After I left the dealership, the handling was very poor.

I'm not mechanically inclined so I don't know how to describe a poor handling car.
- The alignment is spot on, even holds straight under accelaration, decelaration and braking.
- The problem is that it feels as if the car has no sway bars. It seems as if the whole car is made of rubber: During quick left/right steering within the same lane, there is an imediate response, but the whole car seems to trail the steering input.
- Yet another way I can try to describe it is as if the sidewalls of the tires were way higher than they should be (checked multiple times they're the right tire size)
- Finally, it feels as if i'm driving on ice - this is most noticeable at around 65mph and above.

Again, this wasn't a gradual degradation in handling, but a sudden scew-up after tire change and alignment.

What I tried to describe above does not have under exagerated cornering/steering, but is most noticeable at quick left/right input at 70mph (while staying within the same lane).

PART II - What the dealership said
- Took the car back to the dealerhip. A day later i am told over the phone by my service manger that "there is something definetly wrong with the car and they [mechanics] will determine what it is".
- Two days later when I was told I can pick it up I am told that "the car went through extensive computerized testing" as well as drive comparisons against other C350 with same Nitrogen-filled Michelin Pilot and that they handled the same.

That's B.S. I don't think anyone would buy a car that handled like mine. Even my wife told me "what's wrong with the car? IT's so hard to drive, it goes all over the place so easely, there's no way to keep it straight". She wasn't talking that car would pull to one side or another, but that it had a totally numb feeling in the steering and would easerly wander.

Part III - Any ideas?
If anyone has any idea what could be wrong, please let me know. I'm not sure what to do. I'm thinking of taking the car to another place and ask them to test drive and see (a.) if they think there's a problem with the handling and (b.) what the cause might be.

I used to enjoy driving it, now it's a total dissappointment. Thanks for any info!

 

Please look at your tires and let us know the full name of the model of Michelins, with all letters/numbers after the word "Pilot".
Also, a car can go straight, even with an improper alignment...just had that condition on my E350.

 

Some additional info

Michelin Pilot HX MXM4
225 45 R17 front
245 40 R17 rear
40 PSI rear and 38 front (with Nitrogen). (the service invoice indicated 36 PSI all around)

I'd be very happy if it is just a simple alignment issue - will soon take it either to another MB dealership or other place to get it checked.

Regarding wheel alignment: thanks for mentioning that not all is good even if the car tracks straight. So i just read some interesting bits on toe, camber and caster http://www.ozebiz.com.au/racetech/theory/align.html

Interesting stuff... maybe my toe is good but camber too much negative Okay, i don't know what im talking about.

 

My guess is there is more play in the sidewalls.

I had a simillar situation with my clk a few years back. Different tires destroyed the handling.

 

You got all season tires that may explain your problem, all season tires do not handle like Z rated tires, just take the nitrogen out and inflate the tires to the correct specified PSI

 

Sorry, but on my 08 C300, the door piller label recommends 28 in front and 33 in back.

Since I drive my car with the trunk empty and usually either just 1 or 2 people, I get the best drive and tire wear with the fronts at 27.5 and rear 31.

In other threads we found that certain models had other recommended tire pressures but I think that had mostly to do with 4 wheel drive.

Do take a look at it. This might be the easiest fix you'll find.

Also, after running nitrogen for 3.5 years, I returned the nitrogen cylinder this past week. After researching, I now believe that its mostly a snow job. Air is 80% nitrogen and if you leak out the oxygen more rapidly that nitrogen, it'd follow that after some refills the tire would mostly be almost all nitrogen anyway. Plus what applies to airplane and racecar tires doesn't necessarily transfer to domestic car tires.

 

I suggest asking the dealership to change them back to the trye brand you had originally.

A happy customer is a loyal customer !!

IMHO it seems impractital to have different tyre sizes front & rear ie regarding the spare & rotation.Is the benifit worth the complication?

 

You can't even adjust castor & camber unless you fit the fluted 3 way bolts - see here.

https://mbworld.org/forums/c-class-w...any-ideas.html

Michelin PS2's or Pilot Exalto PE2's are a perfect match for this car.

Michelin tyres in general tighten up the turn-in on these cars. I presume you are not over steering it?

 

And:

https://mbworld.org/forums/c-class-w...+rear+toe+W204

 

I have these same tires on my 2010 and they are DEFINITELY NOT made for spirited driving. The are great for just normal driving in all seasons. I went from a BMW Z4 with the Sport package to this car and found myself pushing through a turn the first day I was driving it. Then I remembered the tires that were on it.

 

Good morning and Happy Mother's Day to all!!

Sorry to relay that you have about the lowest rated Michelin tires out there...

http://www.tirerack.com/tires/survey....jsp?type=GTAS

Your tires are also significantly over-inflated. Don't worry about the nitrogen, which is more marketing than real benefit. Without significant emptying and refill procedures, (unlikely at the dealer where each minute = $$) the added nitrogen blended with much air already in the uninflated tire. At least take them back down to the values posted on the label on your driver door jamb which should somewhat improve distribution of pressure across the tire contact patch, limited as those tires may be.

Definitely go for an alignment check, not necessarily a dealer. Is there a place around you which specializes in MB, BMW maintenance/restoration/bodywork? With some of these, you can stand there with the tech while they check and work and see the screen measure the current settings versus spec. BTW, after a 90 degree turn, does the steering wheel feel different as it returns to straight ahead?

The tires are not helping, but shouldn't alone cause the symptoms you are having. I would first suspect alignment.

 

Thank you everyone for the info and recommendations - much appreciated.

First off, I made a uninformed decission and let the dealership decide what tires to get. My mistake. A 15 minute search would have helped a lot - lesson learned.

So I'll do this

1. reduce the tire pressure from 40 PSI to recommended value on the driver's side door
2. Ask someone knowledgeable test drive my car and confirm that the handling problem is really as bad/dissappointing as i think it is (or tell me it's mostly me)
3. Check the alignment a third time (I doubt the dealearship got it wrong twice in a row, so unfortunately resolving the handling might not be just as easy as having the alignment done right)
4. Get different tires. I can't afford to pay for another set so that is not a likely option.
5. Live with it? That would suck. The handling haracteristics are what I really liked about the car (minus the lack of steering "resistance" or feedback)

Because the car handled very well the day i dropped off the car for the tire change and aligment, but morphed into a what it is now when I got it back, it should not be hard to figure out what's wrong, i hope.

And to thank you for your help here are some photos of my C350 that i've taken some years back, shortly after i bought it















Thanks again and I'll post back with an update.

 

I hope you get it resolved soon. Keep us updated.
btw,... great pictures!!

 

One last possibility...not sure how long you had the tires, but Continental has a policy that allows you to exchange new tires in the first 30 days, if you are displeased, for another model they make. Michelin may have the same...and it may be worth calling them to plead your case and ask if they will let you pay the difference for Pilot Sport A/S Plus for quite a boost in handling!

 

Same thing happened to my mom. They swapped her tires with cooper somethings and they sucked. I took the car back 2 days later and they made good. I got her falkens from the shop I use and they mounted and balanced them but she paid for that ($60). they probably resold the tires to someone else. Most major brands honor the 30 day policy, just upgrade to better tires, those are entry level rubbers

 

It is worth knowing what your "pre" and "post" alignment values were/are.

Your old geometry may have been conducive to handling versus stock speck.

 

Nice pictures and no wonder 40PSI

 

Those Pilots are comfort all seasons...not a great tire.

Also keep in mind it takes a few hundred miles to wear off the release agents coating the tire treads...plus you are used to worn tires / tread blocks not flexing like on new tire.

Maybe take it on a road with no cars and do a bunch of hard braking and direction changes to get the release coating off the treads and shoulders earlier - see if it makes a difference and have enough time to return them if not.

 

I could not disagree more, one will not find many tires superior to those made by Michelin. I will cite 7 years in that industry as a professional; not a consumer. How many years as a tire professional do you have to support your position?


The problem is more likely the new alignment than the tires.

I can add neg camber to your car and it will handle like a champ but will drag per revolution rather than roll.

 

Just my two cents...

I've been happily running my tires at 39/40 psi all around - as per my service advisor's suggestion... no more annoying low tire pressure, "correct tire pressure" lights... and I too had a bad tire experience and am the happy owner of Goodyear Eagle GTs - they handle quite well, not too noisy, etc.

I temporarily (a few months) had a set of Pirelli P-Zero Nero All Season Run Flats - YIKES! Besides the fact that I hated them due to road noise, vibration, and in general crappy handling, they met an early demise a few months in as I drove over a bag of screws at the Home Depot parking lot, the bag of screws getting attached to my front driver's side tire, breaking apart, and spreading screws all over the place and getting lodged in two of my other tires. The runflats did exactly what they were supposed to -- I drove them to the auto place the next morning with almost no pressure in 3 of my tires, and it had the same $h!tty handling as when they were new.

Just my input ;-)

 

No one is condemning Michelin...they are among the finest. But, with the breadth of their product line, they also have a low performer. The OP happened to get those put on his vehicle. If you review large sample data as well as testing results on the very credible tirerack.com, you will find the majority of Michelin tires very highly rated...but not the MXM4.

As you probably also know, there is a difference between aftermarket tires, and those produced to OE specs, with OE tires excelling in fuel economy and durability, but usually suffering for performance. Whether or not the MB dealer supplied OE spec or aftermarket tires is not clear. I offer my position from 26 years in the automobile manufacturing business as part of one of the domestics.

Having said that, I still maintain the number one suspect remains the alignment.

 

I concur with this because I have the same tires as the OP and don't have the problems he is describing. They were on the car when I purchased it.

 

You really should read up on how to reset the the Tire Pressure Management System so that it correctly monitors the tire pressure.

Since the center tread wore faster than the side tread on my rear tires using 33 psi, I'm pretty sure that running them at 39/40 would wear them even faster...plus ride hard as heck.

 

...and most people's experience with the MXM4s are the original tires that came with their car which were made of a harder rubber compound to improve their fuel economy.

Buy replacement MXM4s and see how much better they ride.

 

I replaced my OEM MXM4's with the Michelin Pilot Sport AS+. They were less expensive than the MXM4's but have better temp and traction ratings and the real-life performance is incredible. I experienced excessive understeer before the replacement. Now, the car grips like a go-kart. They are also better in wet conditions.