blee911

I've noticed the ride quality has deteriorated significantly since I bought the car 14 months ago. I've put 24,000 miles on the car but the stock tires appear to have plenty of tread left. I know the run flats are known to compromise ride quality but this seems worse. The car doesn't ride smooth over bumps --- alot of thudding felt and heard over road bumps, even change lane markers at lower speeds. Tires are currently shown at ~30psi (45-55 degrees in Northern California). I bought this car with the adjustable air suspension option. Wondering if something is going on with the suspension, the run flats get worse over time, and/or if anyone's had similar issues. Have an appt with the dealer next week.

Fourdiesel

I've not heard of this type of issue, but if you can talk the dealer into temporarily slapping another set of tires and wheels on then giving it a test ride you should be able to easily tell if the tires are the culprit. That option is a lot easier than changing suspension control black boxes!

aeggroup

No doubt it's your tires. I changed my run flats when they were about 5K miles and the difference is huge . I can imagine how bad they are when they get to 25K.

jchochla

I'm in Michigan, and i've noticed the same.My GL has 18K miles on it. My steering wheel has gotten very loose(took it to the dealer, they tightened something, it was fine for a week, then got loose again). And when ever i go out a small pot hole, i can hear the car going over it, much louder than my 2011 Ford Edge Limited(has 11K miles on it).

Im taking it in this week, Friday or Saturday. Im pretty good friends with the head mechanic there. I feel like something in the front suspension is broken. I drove my neighbors GL about 2 days ago, and its not nearly as bad as mine. I'll keep you guys updated!
John

lkchris

Reduced tread depth (due to wear) reduceds tire's ability to "squirm" and provide soft, quiet ride.

So does fact the rubber is aging and losing pliability.

mdadgar

No.

Yes.

Also, colder weather = stiffer rubber = harder sidewalls = rougher ride.

- Mark

aeggroup

Can't agree with that. Somehow my "regular tires" ride is still the same - winter or summer.

43221B

Also, as it gets colder, any cracks that have been in the road all summer are going to get wider as the asphalt contracts making them more noticeable. I have 33,000 on my Goodyear runflats. I have noticed the same thing every fall/early winter.

mdadgar

Different tires, different rubber, etc etc etc.

I could be wrong (unlike lkchris), but given the already stiff sidewalls and hard rubber content of the GL tires, it makes sense.

- Mark

blee911

Thanks for everyone's feedback. I'm looking forward to what John finds out with his GL with 18K miles. I'll also keep you posted on what happens at the dealer next week.

For those of you who changed out your run flats, what tires did you go with and what do you plan to do in the event of a flat tire? Did you purchase a tire repair kit? My old Cayenne S came with no spare and non-run flats but had a tire repair kit which included a small compressor that connects to the battery. Seems crazy and high impractical coming from Porsche but I actually did have a flat tire once and used the compressor so that I could make it to a nearby tire store.

We make a lot of trip to Tahoe during ski season. How does the ride compare for Scorpions vs the stock runflats. I hear snow tires aren't great when you don't need them but I can't imagine anything being worse than the stock run flats.

jchochla

I'll for sure get back to you on what they say. I'll take it in tomorrow or Saturday.

aeggroup

I changed my original Bridgestones to HANKOOK - VENTUS ST RH06 285/50R20. They were much cheaper than original 275 size. As I said before - the ride is totally different - no road noise and very smooth.

Also I bought this repair kit from ebay :

http://www.ebay.com/itm/400247804177...ht_1702wt_1110

blee911

Thanks! How many miles have you put on the Hankooks and how do they look? Not too wide for the stock rims? The 275/50 Goodyears already stick out a bit.

HIGHMILE E55

Mine had an issue like this where the ride deteriorated. It wasnt the wheels, rather it was the rear shock absorbers that started leaking oil .

I first thought that being airmatic, that it didnt have/need shock absorbers - but yes - it still has those in there for dampening. When they went south, the ride was worse than my 4Runner. After it was fixed, it was like night and day..

jchochla

Highmile, before the problem got solved, were you able to feel if you went over a bump or pothole in your steering wheel? Because my car's been in already once. But i have my work schedule pushed back, so i will either take my GL to the dealer tomorrow (sat morning) or next week.

aeggroup

Hi.

I put about 2K miles..not a lot. I wouldn't say they look much different than stock tires. Here is couple pics I just made :

HIGHMILE E55

Yes I especially felt (and heard) the bumps and potholes more than usual. Now that I think about it, I remembered that they also replaced one ball joint. The symptom of the ball joint was that the car did a slight wobble, when going over a pothole.

It was really night and day after they fixed the suspension issues - you can definitely tell the difference. It made me realize again how amazing this thing is when everything works the way it should...

jchochla

Sounds good. I made a appoitment for this Thursday. I'll drop it off and let them have it untill they fix the issue. While the GL goes to the shop, I'll drive my E. I'll keep you guys updated!

blee911

Just dropped my car off at the dealer in San Jose. Even the C-class loaner has a much smoother ride than my GL! Will keep you all posted.

blee911

Dealer found nothing unusual. 2 techs drove my car. Service advisor said I could come in and test drive a new GL for comparison. I'll let you know what I find. I'm certain the ride wasn't like this before but if it is a function of run flat wear then I can see how MB would classify this as within normal operating performance...not that I agree. I never would've considered buying a GL if I knew the ride would be like this after 1 year.

43221B

My Goodyear Runflats have >33,000 and they are no different than new in terms of ride quality. I do think the sidewalls might get a little stiff when it is cold but really not too noticeable.

I'm pretty sensitive to how the tires feel too. After my last service (30,000 miles) I left for a 5 hour trip. I almost immediately noticed that the tires felt harsh. After hours of feeling every little imperfection in the road, I got to my destination and checked the tire pressure. As I had assumed, the MB tech had put 38 lbs of pressure in my rear tires (as they always do, I guess they must think my toddlers are fat or something). I brought the pressure back down to 32 and all was fine.

I would take the service adviser up on his/her offer and bring your own tire pressure gauge with you.

aeggroup

No reason to worry. Just change the damn tires and forget it.

jchochla

^There's a solution...lol.

blee911

Finally got an honest answer from one of the Sales guys and he said his MB has the same problem and it's those darn runflats. The service guys will never admit problems like this.

Thanks for all the inputs.

mdadgar

I would love to go to a regular tire, but Tire Rack shows no all-weather options in the same size that are not the GY or Bridgestone run flats. Really? Suck.

- Mark