I love a soft ride. Considering c300 and c43. One of many factors for me is smoothness over rough roads with bumps or vibrations or potholes. In other words I like soft suspension. This is obviously not my only factor on c300 versus c43 but I’d like to understand which would be softer.

C300 has no adaptive suspension but is supposedly softer by default? C43 has adaptive suspension and I’ve seen some hints / claims that in comfort mode it would be softer than c300, but then other people say that c43 even in comfort is still firmer.

Please let me know your experiences and/or your understanding.

Edit - let’s assume same wheels and tires of course

Unfortunately, this is somewhat subjective and depends on the roads you drive on. The C300 has what they call selective damping. The dampers have two settings, soft and sporty and the suspension switches between them depending on your driving. When it detects lots of body movement or higher cornering forces for example it switches the dampers to the firmer setting, and then back to the softer setting when you are just cruising along, however, as the driver you don't have direct control over it, and it's not adaptive as said. It doesn't continuously adjust the damping.

The selective damping suspension in the previous C300 was frankly not very good. The comfort variant was super floaty, and the sport variant was kinda harsh. I still remember driving a C300 coupe loaner one time, which has the sport suspension standard and I was amazed at how bouncy the ride was on the highway. My 2019 C63S coupe, which one would expect to be less comfortable, was way smoother on the same highway thanks to the adaptive damping. As opposed to the C300, the adaptive damping in the C63 keeps the body controlled and momentary bumps are quickly absorbed. It cruises much calmer instead of bouncing around over every bump. However, the springs are still firmer, so the initial impact of a bump is felt much more in my C63 than it was in the C300 with sport suspension.

But this brings me to the main issue with comparing suspensions. Firmness is only one part of the suspension. Damping is the other. You can have a fairly firm suspension, but if the damping is done well it can actually be more comfortable. This is how I feel about my C63S in general. The springs are fairly firm, but the damping is great, so as described above, the ride is comfortable except for really bad roads, because the damping keeps the body of the car calm. I don't bounce all over in my seat just driving along on the highway for example. It actually gets smoother the faster I drive, with a level of luxurious wafting in Comfort mode.

FWIW, I haven't driven the new C43, but I've had a new C300 AMG line loaner twice. The selective damping suspension is now much better, even in the AMG line sport version. The car rides quite nice. The C300 is overall too soft and too lame for me, but it drives better than the previous generation. Unfortunately, the interior feels cheaper and is way less ergonomic with having to operate everything via the touchscreen and the capacitive buttons are total garbage. Not to mention that MBUX was super buggy and CarPlay kept disconnecting and was essentially unusable. Supposedly they've pushed out updates to fix some of these issues, but this loaner's system was total crap.

The gist is you gonna have to drive these cars on your typical roads to know which one suits you better. Nobody here can really tell you. I like to feel the road even when driving around normally, but at the same time I don't wanna be beat up every time, so only you can decide what feels comfortable to you. But I am gonna say that adaptive suspensions tend to have an edge, because they can blend the opposite goals of comfort and handling, plus as the driver you can choose between three modes for the base level of damping, so you are much more in control then with a fixed suspension or the selective damping suspension in the C300. For example I usually put my suspension in Sport mode for highway driving, because I find Comfort mode a bit too soft for when I'm doing quick lane changes and such, but I put it in Comfort for longer trips.

^ I echo what he said especially the selective suspension in the C300. One of its biggest flaws is that it is fluid based and it reacts to body movements. The sharper they are the stiffer it gets. Unfortunately on really poor roads the harsh body movements stiffen the fluid making it rather uncomfortable.

Go for a base non-AMG line car. It’ll be the smoothest by far but still no baby S-class. Considering your priorities, I wouldn’t expect you to want something overly low to daily drive. The W206 is more of less half an inch lower than the W205 in every trim, and the W205 was already low enough as it is. My AMG-line W205 will sometimes bottom out speed bumps if I have 3 or 4 people in the car, no matter the angle or the speed. Some of the hilly California driveways are just the most stressful things too. The AMG-line suspension cars are lowered about half an inch compared to base and are the same height as the C43. If the new W206 is already have an inch lower overall, this would mean that the new base C300 would sit about as high as mine, with the AMG-line and C43 both being about another half an inch lower than that. I remember a thread of owners complaining that these were too low back in 2022 when they first hit the market.

I knew what I was getting into with my W205 as I was looking for exactly that, but it means I have to stay somewhat vigilant. Sometimes it gets stressful as I drive downtown over poor, old train tracks that I can’t take as quickly as SUVs because of my lack of clearance (we have really poor roads here). Many will be fine with the ride height but some won’t and they end up complaining afterwards because they weren’t aware. My salesman told me that he started warning people looking at AMG-line cars because too many would come back and complain that the car was too stiff or too low.

The W206 AMG-line suspension is softer than it was in the W205 and definitely more comfortable than the full fledged C63. However, compared to the base car and the average Camry or Accord it is definitely quite a bit stiffer.

c43 comfort + 18 inch wheels has to be pretty plush on the spectrum

I owned a 2023 C300 and traded it recently for a 2023 C43 AMG. The C300 had 19's and the AMG has 20's. The ride is significantly harsher and road noise much higher in the AMG, even in comfort and after the run-in period. They are like two different cars! However, the power, handling, performance and driving excitement of the AMG blow the C300 away. Trade-offs

Answers above very much appreciated. Also relevant:

Any AMG is going to be firmer than the standard model. If you like a soft suspension the C 43 is not for you.

Yeah leaning towards c300. In my perfect world I’d have the c300 suspension with the c43 engine. Why can’t I have my cake and eat it too?

You could always tune the 300 although your warranty would be voided, and tuning options are scarce, expensive and won’t give you close to that full 43 power.

If you were thinking of a C43 I would wager that you can also likely afford an E-Class? They are out of production, however there should be leftover W213 models on the market. If you don't mind the increase in size, the E-Class rides extremely well and has a similar engine to the C300, albeit without the mild-hybrid (unless opting for the E450 and its 6-Cylinder). Otherwise, like others have said, I'd find a C300 without the AMG-Line package and smaller rims. Also check out competitors, the Audi A4 also rides very well. The 330i will be sportier, but not too harsh if you get smaller wheels.

Like other said get an e350 with acoustic comfort package & the air suspension. Had one for a few weeks & man it’s sooo smooth and quiet. Very soft suspension but not so much that it wobbles on the highway. Or better if you can get the last gen s class and call it a day. C43 or anything amg is not for you based on how you like sof suspension

Yeah this thread has helped me appreciate the role of air suspension (as opposed to active dampers) and yes that has led me to look at e class. C43 would be a $ stretch for me, so then considering an e450 is too much $$ and I’m back to considering a c300 or e350 and giving up the dream of occasional speed/power. I’m facing the reality that I can’t have powerful/fast, less expensive, *and* truly soft ride. Can only have two of those three. Classic dilemma. Toss on top that I can’t live without touchscreen, ruling out some preowned, or taking me down path of preowned e450 + aftermarket head unit which makes me a bit nervous.

which model year was that btw (regrading the e350)?

Facelifted E-Class’ (2021+) have both touchscreen and trackpad capabilities. An E350 is a great choice in my opinion if you don’t mind a 4-Cylinder. I would not install an aftermarket head unit in a car that new.

The standard suspension of the E is very comfortable already, not quite sure if still true but it used to be standard suspension then dynamic body control then air body control (ABC). If you are planning to keep the car for a while we will not advise you to get air suspension because those could fail and when it does it gets expensive, not having run-flats and have proper tires (that are known to be quiet) also helps, smaller wheels like getting 18s over 19s also help. The E 350 yes has to move more weight than the C 300 can still be pretty capable. At the end of the day though, you would want to test drive to make sure it is what you want plus need.