Denis Osullivan

I just picked up a 2018 S560 with 19k miles
The ride over 55 seems too rough so I checked the tire pressure. On the B pillar is says 43psi. On the gas tank flap it says 35 psi. These are Runflats.

I lowered the PSI to 35 which slightly improved the softness but still not smooth.

Which PSIdo I follow?

I also recognize that the front rotors need to be changed out as braking is not smooth also.

Will rotors also create a less that smooth ride over 55mph?

any thoughts? Thanks

Tom in Austin

My understanding is you're supposed to follow the label on the gas filler flap. Even that has two or three sets of numbers depending what size tires and wheels your car has.

flint350

Tire pressure on the fuel fill door is the pressure that should be used. Tire pressure on the driver's door jamb is max pressure limit and not the everyday pressure.

Denis Osullivan

I purchased the car via MB dealership and they had pressure at 43psi. It makes you wonder what other items they touched/fixed incorrectly.

I'll be replacing the rotors and brakes myself.

emilner

It should be smooth as silk- what size tires/rims?

hyperion667

That is what I was going to ask

Denis Osullivan

19” AMG five spoke

emilner

Then something is wrong, if you said 20's I could say it is likely rim size plus tires. On 19's the S560 is just about the smoothest riding vehicle ever made...

MBNUT1

Even with runflats?

emilner

My 2019 with 19's and RFTs is smoother than my 2015 S550 with Michelin non-RFTs. There is a reason every review I have ever seen has said it's the benchmark for smooth ride (not cross referencing RR or Bentley).

Denis Osullivan

I’ll get the tires and rim balanced and see if that corrects it.
if one of these run flat tires is bad, how would I know? I never had this type of tire.

as.thompson

As far as tire failures, RFs are the same as other tires. Just that the sidewalls are stiffer to support more weight than non RF tires in case of a loss of internal pressure. Of themselves they shouldn't cause a vibration noticeable at speeds above 55. That sounds like balancing and/or perhaps something in the suspension loosening with wear.

dweb4

I don't want to make you upset after purchasing the vehicle but look also at a bent rim/s. I know it's not what you want to hear out the gate but at the speed you mention I had a bent rim and wasn't noticeable until you get over 55 plus where the vibration translates back into the vehicle.

Denis Osullivan

I’m hoping that it’s just a rim. I have the wheel and tire policy but doubt the dealer will repair under this policy as the tire hasn’t lost any air.
Has anyone had experience with rejection of this policy on their bend rims?

kafklatsch

Hi, can you link/point to a few reviews... I have not heard of the RFT being smoother than the nons... i really want to read more...it would try be great if they figured it out for 2019... 2015 (and maybe 2017) are much smoother and super quiet without RFT... but instead with quiettracks.... my 2017 not needed tires yet... but not as smooth and quiet as the 2015 right now with the nonRFT...

CAN others chime in on 2019 RFT tire smoothness and quietness - RFT vs nonRFT....

I do understand that smoothness is in the a$$ of the beholder...

emilner

Just look at any review of the S560. It is over and over and over referred to as the benchmark for ride quality. Some people on this forum make it out to be a 1970's lifted pickup truck...

PatentLawyer

My S560 on 18" runflat Bridgestones is excellent. Noticeably better than my S450 on 19" AMG with Pirelli runflat, but not by miles. That car also rode fantastically; impacts were harsher, though. I can't imagine how 18" non-run flats would ride.....Magic Carpet?

as.thompson

I second that possibility. I somehow ended up with a bent rim. But the good news is that it didn't cost me much to straighten it - $45.00 at a local wheel refinisher.

Denis Osullivan

Update

Four rims bent. Straightened and balanced within 1.5 hours.

Car ride is like silky smooth.

Shout out to Dunn Wheels, Bronx, NY

This shop said to inflate to 42/43 PSI

emilner

Glad to hear but that is a very high psi. It will cause a harsher ride and poor tire wear.

Baltistyle

I wonder since you mentioned getting all four wheels repaired in the Bronx, is this a city vehicle? I ask because you may WANT a higher psi due to the chance of continuous bent rims. You don’t want it to be jarring or kill tires, but there will be a happy medium.

glad you got it straitened out, pun intended.

Now, go send that dealership the bill for a good laugh. It would really now be best to go to a trusted Indy and have them fix or repair everything that dealership neglected to do or possibly messed up. A proper baseline won’t cost too much and will ensure your continued proper enjoyment of what many say is the quintessential elite sedan, that everyone can aspire too.

SW20S

I wouldnt run the PSI that high...

Denis Osullivan

Since you’re against this high PSI then why is it listed on the B pillar??

emilner

I believe that is the max psi (extra load). The correct pressure is located behind the gas door.

SW20S

As emilner said the PSI figures you want to follow are on the fuel door, 35. I actually run 33 and I dont have runflats

If you want a soft ride, 42 PSI isnt gonna give you that lol