Stiff suspension
Thread Starter
Newbie
Joined: Jul 2024
Posts: 12
Likes: 1
S550, S560, GLS450, CLS550, CLS63
Stiff suspension
Hey guys. I have a 2020 s560 4matic. Currently running Michelin pilot sport all season4 245/45/ ZR 19 in the front and 275/40/ ZR19 in the rear. I had a 2015 s550 4matic that was honestly way more comfortable this thing just feels so stiff over bumps. I don’t know tire pressures at the moment but they are around 40 like it suggests on the door jam sticker. Is the reason for the stiffness the zr tires since they’re rated for over 150 mph or is something else wrong. The car has about 79k miles but all suspension components look great. The only thing I can think of is the tires being the style I got makes it a lot stiffer. It does do wonders for handling this boat but I didn’t think about how it might affect the comfortability. I’m just not sure if it’s the tires or something else. Any tips or ideas are appreciated. I’m probably going to get another set of rims anyways so I’ll try other tires to see if that was part of the issue. Thanks in advance.
Out Of Control!!
Joined: Nov 2018
Posts: 11,400
Likes: 5,324
From: San Francisco Bay Area
2019 C63CS
First start with using proper tire pressure. The ones on the door sticker are not the correct ones. Those are only for max load technically as in the car is full of passengers and cargo and you are planning to drive north of 155 mph. So the pressure is higher to handle all that. Open the fuel door flap and look at the sticker on the inside. It lists various pressures for different tires, loads and speeds. Use what’s known as the normal load pressure. 2-3 passengers, little cargo and speeds below 155 mph.
Having said that. Z rated tires will be stiffer, and the lower the profile, the stiffer they are. Just one word of caution, if your roads are bad and you have a habit of driving through potholes, then the lower pressures will give you less protection.
Ultimately, if you want comfort oriented tires, you need to look at touring tires and larger sidewalls. Also, your tires are likely runflats as most cars these days don’t have a spare tire anymore. Those are also stiffer. Many replace them with non-runflats and carry a flat tire kit.
Having said that. Z rated tires will be stiffer, and the lower the profile, the stiffer they are. Just one word of caution, if your roads are bad and you have a habit of driving through potholes, then the lower pressures will give you less protection.
Ultimately, if you want comfort oriented tires, you need to look at touring tires and larger sidewalls. Also, your tires are likely runflats as most cars these days don’t have a spare tire anymore. Those are also stiffer. Many replace them with non-runflats and carry a flat tire kit.
Last edited by superswiss; Yesterday at 03:38 PM.
Senior Member
Joined: Jun 2007
Posts: 457
Likes: 253
From: SD
Various
On my 2020 560 4M I just put on a new set of OEM Michelin run flats and think the ride is fine. No complaints. And I run 33-34 psi.
Edit… I have the tire you’re running on my Fcar and it rides fine. 32-33 psi.
Edit… I have the tire you’re running on my Fcar and it rides fine. 32-33 psi.
Last edited by NbyNW; Today at 08:02 AM.
