I own a 2014 CLS 250 CDI Avantgarde 10 Edition, purchased new, with 19" wheels and standard Pirelli tyres all around, 30's at the front and 35's on the rear. These cars have Airmatic adaptive suspension as standard (at least in Australia). When testing this car before purchase we only drove on smooth roads and everything seemed fine. However, since new on normal roads, with occasional broken surfaces, the ride is appalling. Potholes of any size results in almighty crashing that intrudes the whole cabin, and to be honest I've actually stopped the car occasionally to ensure the rim wasn't damaged. Friends are shocked, one has a Great Wall table top truck that rides better. Similar potholes or broken surfaces would not have fazed my old BMW 5 series. It actually feels like there is absolutely no damping as the wheel drops into the broken road surface, then bounces up way beyond what the suspension can cope with. At the first service I raised this with MB and they said all is in order. I've googled and read every road test on this model, and only 1 has mentioned 'crashy' suspension, all others rave on about smooth ride and waftiness befitting a Mercedes. I've also read reviews on other mercedes models with airmatic, and they all seem to report how much better it is than steel springs. I just cannot understand how this design was passed by MB for Australian roads. One other thing, the noise transmitted inside the cabin by smooth, but coarse tarmac can be almost deafening.
Has anyone else experienced this? Is there a fix to the problem? Is it simply that MB got it wrong with this model and someone can recalibrate the airmatic to suit the car? Im looking for any help coz I'm on the verge of selling this car which would be a shame because in all other respects it is great.
Thanks in advance for any advice.

 

Your truck rides better because the sidewalls are thicker on it. You have 30's and 35's which means your ride will be a lot rougher then if you had the same wheels with 40's and 45's (of course it wont look as good though).

 

Low profile tires do screw up the ride. I have 19" factory AMG wheels and there is a very big difference (huge improvement in ride quality) when the suspension is set to comfort rather than sport.

 

The truck also have a much longer suspension travel. I test drove a CLS with 19" rims, the ride is bumpier on uneven road, that is just a facts of life with low profile tires. OP, try changing out the wheels instead of the car.

 

Thanks for your comments. I know that low profile tyres give a harder ride, but i can't accept the crashiness. I've driven other cars with 30 ratio wheels and the ride can be firm but still supple without the coarse thumping mechanical 'intrusions'. Even the current run-flats on BMWs are smoother (CLS 250's don't have run-flats). As I said , it feels loose, like the rebound damping doesn't exist at all. I've had an independant mechanic test drive the car and he said the airmatic was 'working', and his suggestion was to get larger higher profile tyres. And yes its probably a cheaper in the long run than selling the car and copping all this depreciation! I'm just pissed off that MB is renowned for beautiful riding cars, every other Mercedes I've driven has a lovely ride, that that when i read about airmatic technology it is theoretically fantastic, but in practice, on my car, it is simply awful.
MB now install airmatic on everything from AWDs to C-Classes, so it should suit the CLS.I've never heard about the problem on CLS 350, 400 or 500 models.
Does anyone know whether it is possible to adjust the damping rates on the airmatic? I would assume it is set by the factory for each particular model. Can a qualified mechanic possibly tinker with this? Tell them to adjust the damping to suit a CLS 350, and see what it feels like?

 

Hi JonnoH dunno where in Aussie you are but the few times I have visited Sydney and Adelaide, roads seemed a bit ( or sometimes a lot) better than here in the northeast of the US.


I have a 14 CLS550 with airmatic. The damper controls are on the right of the Comand controller and mine select either comfort or sport. Definitely feel the bumps more in sport but nothing too terrible. Potholes can be jarring here in the northeast due to winter, road salt etc etc. I ride on 18s and not 19s because of the tough road conditions and I think that is the right choice for northeasterners. I know many CLS550s in the south of the country ride on 19s cos the roads there are less affected by potholes through the winter. Suggest you switch to 18s if the harshness of the 19s bother you.


On some BMW forums I have read about shipping blocks that they place in the suspension for shipping enroute. There was a BMW 6 series owner who found the shipping blocks not removed from his suspension and that explained his jarring ride. Never heard of that happening with a CLS in the US as yet though.

 

Dunno which tires you have there on your 19s but I have Conti Pro Contact all seasons on my 18s. They are good when new but after you have say 15k miles on them, they do get noisier. Many German makes use the Conti Pro Contact as OEM tires and a Panamera I test drove was pretty noisy riding on those tires cos they were down to about half of tread life. I have lived with noisy tires on other cars and two solutions usually work for me - turn up the stereo and eventually, buy new tires.

 

I have the 19's and the ride is substantially rougher and noisier, particularly at high speeds (even on "comfort") than my CL55 (2004) which has 18's. At speeds under 50 or so, it isn't noticeable, but at highway speeds, you definitely hear it/feel it.

 

OBP and JHouse, thanks for your input. OBP I have Pirelli PZero's all round, and my experience with these are excellent. I had them on my old 5 series for 10 years and they are relatively quiet compared to Bridgestone and Michelen which I also tried. I've never tried Conti's though.
It would seem there is an enormous difference between 18s and 19s.From all your comments this makes a huge difference. I can't understand why MB fit 19s as standard in Australia knowing it completely negates all the smooth-ride technology built into these cars. It doesn't make sense. I did some more research yesterday and the Airmatic with ADS II cannot be manually tuned. Its computer driven and damping changes dynamically all the time depending on a whole bunch of inputs. I'd like to think MB is aware of this problem and can possibly update the software that drives this.(Are there any MB mechanics out there that can tell me if airmatic software is ever upgraded during services??)
Interestingly, last night I was reading an article in the current 'CAR' magazine (published in the UK), comparing the MB S-class 350 with the latest BMW 7 series and Porsche Panamera. It says the Mercedes has the best ride, until it hits a bad surface or pothole, and then it crashes intrusively into the cabin. Hey what! Even in an S-class? The big BMW is unfazed by similar road surfaces. To me it seems as if the Airmatic gets all relaxed on smooth roads, and is asleep on the job when it needs to suddenly do some heavy damping. So this problem is not just my car, but possibly all MB cars with airmatic on 19s.
So to avoid the cost of buying new wheels i will investigate whether i can fit higher ratio tyres front and back, hopefully there is enough space in the wheel arches to allow this to happen. And hopefully if i can get, say 40's (front) and 45's (back) to fit in there, it will make a big difference to the ride. Only problem then is the wheels are not to spec, and what would an insurance company say if the car was damaged, if say a blow-out occurred.
By the way, anyone out there actually tried higher ratio tyres on 19s? Any difference noticed?

 

40s and 45's are going to be pretty big sidewalls. But if you are more concerned with comfort (which it sounds like you are) then looks and performance, then thats going to be your best bet, especially if you live in an area with really bad roads.
As far as if you have a blow out goes.. I don't know how it is in Australia, but here in the U.S. if you have a blow out they most likely would sue the tire manufacturer. Our insurance companies cant tell us what is in spec and what is not. I bought my car with some conti's that have 35's in the back and 40's in the front. Its really a smooth ride, but Im going to be getting 20" wheels and running 255/35 in front and 305/30 in the rear, so I am expecting a rougher ride.

 

The CLS does bottom out easily, I am guessing that it is due to its short suspension travel which by the way is why it handles so well.

 

The few comments I have read about P Zeros over here in the US are less favorable than the Conti Pro Contacts.


With a higher aspect ratio tire, assuming you have the correct inflation pressure, chances of a blowout due to irregular roads are lower, not higher, than with lower aspect ratios. I tend to do a little overkill myself - I run my inflation pressure at least 10% higher than recommended by the OEM and it gives me more resilience against blowouts/tire bubbles due to potholes. But then you get a harder ride that way ... I am OK with that - a few bumps are better than having to get a tire changed or a rim repaired.

 

RacingFish maybe 40s and 45's won't fit however i'm hoping something higher than 30s and 35s, which is what you are aiming at. Can't imagine why you want to risk losing a smooth ride if you have one now, though I have to admit my car turns like a sports car, suppose thats what the big wheel/tyre combos are supposed to do.
I also note that you have the CLS550 giving extra weight over the front, whereas my 2.1 litre diesel is the lightest. I'm guessing more weight over the front might make all he difference, adding suppleness. Mine feels like it needs more weight to stop the trashiness. When you get the new wheels I'd be interested if you post how it feels.
Are you going with Continental's? Not so common over here in Australia but I might have to look at these next time.

 

I have a 2012 and picked it up used and thought the same, it does get clunky/crashy on certain lumps in the road, sometimes driveways, uneven or deep manholes etc...

I brought it into the dealer thinking the ball joints were gone, but they checked it out and found nothing wrong with it. I also have the 19" rims with factory Pirelli tires so I've chalked it up to that.

 

I live in arizona, we dont have potholes out here. Im actually going to be running 255/30/20 and 295/25/20... its gonna be rough. I run 35's on Subaru that has teeth rattling suspension. So I'm pretty use to rough rides, I like to feel the road as I drive tho... =(