I recently put new 18" Michelin Pilot MXM4 on my 2002 SL500 (it has the Sport Package) and the ride was very smooth and handling was very good. My mechanic suggested these vs. Z rated tires for a smoother, quieter ride.

After driving over a very rough patch on the freeway I have developed a vibration in the car. The car now rides hard (not just firm) like going over a rough road (even when the road is smooth). I have had all of the suspension components checked and everything is fine; no damage. I also had the wheels and tires high speed balanced, put back on the car and still a rough ride. At that point I replaced the "new" tires with another new set of the same tires and had them high speed balanced. The date codes are 2008 so they are new tires. The vibration is less but it still rides harder and bumpier than it should. The car has been in the mechanic shop for over a month trying to solve this riddle. At this point we are at a loss as to where to go short of changing tires again. Has anyone else had a similar problem with vibration/rough ride with their SL500? I have read both positive and negative reviews of Michelin tires with regard to ride quality, tread life and early separation.

I have the following questions:
a) Has Michelin had a problem with their tires?
b) Would changing to Bridgestone Potenza RE960AS tires be a better
choice for ride quality and interior noise? Does anyone have experience
with this tire on their R129 SL500?
c) How about the Michelin Pilot Sport PS2? Experience?
d) Is there a recommended optimum tire for my 2002 SL500?

Any input would be greatly appreciated.
Thank you in advance,
Mike

 

With regard to 4, Tirerack.com suggests 245/40R18 front and 275/35R18 rear. I have found their suggested sizes have been fairly accurate. Unlike other cars listed there, unfortunately, there are no OEM tires listed.
Just out of curiousity what pressure are you running? A hard pressure on MBs will severely change the dynamics of any car. Doesn't explain the change though after a rough ride.

 

Thank you for the quick reply. The tires are the recommended sizes as you stated. I am running 33 psi in the front and 36 psi in the rear as MB recommends. I had replaced the front two tires first and then drove the car. It was still rough. Then replaced the rear tires and it is a little better. Since these tires are only about 3 months old with less than 100 miles on them I am wondering if I am dealing with a tire manufacturing problem.

 

While tires can have manufacturing defects, I would think the odds of four tires in two different sizes being a problem are astronomical. But anythings possible.
From your Original Post, a rough piece of road changed the dynamics of the car. While I know zip about the suspension in your car I suspect something is out-of-kilter.
Sorry I can't be of more help.

 

I recently had installed a set of Michelin Pilot Exalto 225/55 R16 s on my 96 SL500. I had much vibration at speed (75) and returned to the dealer. I had thrown the weights. New stick on weights were installed on the inside of the wheels after high speed (roadforce?) balancing. Still similar problems but felt more like the rear than the front (Incidentally air pressure at 30 and 32 F/R as noted in door frame). Tire dealer suggested drive shaft causing the problem. Took to another mechanic who suggested that drive shaft problems don't happen? when you purchase tires. We put the car on the rack with a driver inside. We watched noticeable squirm of the tread as the tires were spun (rear). Went back to the tire dealer who suggested that they had difficulty balancing one of the tires but his manager would not allow him to swap it out. Manager left for the day, tire swapped out, all is fine. I'm $79 poorer and 8 hours (returns complaints and waits) because some manager wanted to sell a "bad" tire. I may not go back. ever. This particular tire dealer has been "servicing" 3 cars for me. I wonder if he feels it was worth it.

 

Your experience seems to be one more complaint of defective Michelin tires. The tire dealer is agreeable to let me change these tires to another brand. I am considering either the Bridgestone Potenza RE960AS or a Continental Extreme Contact. Does anyone have any experience with either of these two with regard to ride, road noise and handling?
Thanks,
Mike

 

I had these installed on a car several years ago. They were grippy, quiet, and smooth. They lasted about half as long as the original equipment tires. Probably the soft compound. I would consider the treadwear numbers in purchasing. Most dealers will tell you if a tire is noisey. Especially if you make it clear that the tires will be coming back if they are!!

 

Problem solved. I replaced the Michelin Pilot MXM4 tires with Bridgestone RE960AS tires and there is no comparison. The ride is smooth, quiet and the handling is a great improvement over the Michelins. I will stick with Bridgestone from now on.
Thank you to all who replied.
Regards,
Mike