DavidC87

Hey everyone, just picked up an S400h (Asian market) today and so far loving it to bits except for one thing: the ride. It feels quite unsettled on the relatively smooth highway, even though the suspension itself is great at absorbing proper bumps and potholes. I feel like there's a sort of jitteriness and anxiousness to the way that the car travels over seemingly smooth pavement, which I'm not sure is normal for this car. I have an F30 that feels way more settled than this.

I'm riding on standard air suspension, and the car came standard with 20 inch rims, for some inexplicable reason, and Pirelli runflats. I used to drive a W221 that rode on 20 inch wheels and summer Continentals, but didn't experience the same unsettled, jittery ride (not vibrations). I've also driven a friend's W222 S550 (on 19 inch wheels with runflats) but experienced a really creamy, buttery ride that I expected from this car. It can't be a tire balancing issue because the car is brand new. So here are my questions:

1. Has anyone ever experienced this with their new car and did the unsettled ride eventually go away?

2. Are the tires the main problem or could I potentially have a bigger issue? I have an F30 with runflats that don't provide the same sense of uneasiness. I don't know how to describe it, but it almost seems like the tires are slightly *uneven* on smooth surfaces, if that makes any sense.

Appreciate anyone's input!

hyperion667

hello and welcome.....could be a combo of the two? the runflats and the 20's?
I don't recall reading anything good about the RF's


hope you work it out so can enjoy your S class!

Steinhart

I have RF's and 20's, ride is very good, especially over smooth pavement, but planning to change to regular tires when these are worn

Chucky300

I have 20s and it came with runflats - took those bricks off and put dunlop supermax gt - totally different. There was a thread on this I started back in 2013 (november / October)

I have not really heard many folks happy with Runflats - especially in BMW forums.

Switch them out - and keep a spare in your garage.

Streamliner

I don't know what it's like in your country, but if I had that problem with a brand new car here in the USA, I'd take the dealer service manager for a ride and ask him if this is normal. Personally, I feel that run flat tires on a luxury sedan are the KISS OF DEATH and I had mine swapped out as part of my deal when I leased the car. To me, ride quality is everything in a big sedan and my S550 rides very quietly and exceedingly comfortably on 18" wheels, with Bridgestone Serenity Plus tires. I also have MBC. Go complain to the dealer and tell them how much you hate the RFT and not having a jack & spare in your trunk.

Iridium222

IMO I think that since you are on the stock 20's with RFTs, you are experiencing a harsh ride quality. My W222 S550 also came with Pirelli RFTs but with the 19" stockers. Also, IIRC many forum members have mentioned before that although the 20" stockers look great, they're very uncomfortable.

e_dasani

I have 20" and RF's, the ride is silky smooth and I am happy. I had earlier test driven with 19" RF, and to me the ride was same. So while I truly value opinions on non-RF's, but i'm also skeptical, if swapping them really make significant improvements to what already feels pretty good.

DavidC87

So after two days of running, there's been a noticeable improvement in the ride quality. I'll definitely try switching to regular summer tires (speaking of which, any recommendations? I've seen Bridgestone Serenities pop up here and there) after this set is done. Road noise and ride aren't so unacceptable that I could justify throwing them out basically new. Thanks for all the comments guys!

Steinhart

I wonder if the car had been sitting for some time, which resulted in a flat spot on the tires. That may have been the problem. Not sure what else could improve after driving it for a while, that would result in a better ride.

DavidC87

Car finished assembly about a week before I got it, so I doubt it's been sitting for too long. Honestly, I'd attribute it to desensitization. I asked a friend who drives a W222 about his experience with RFs and 19'' wheels overseas, and he told me that sometimes he too experiences what I describe when he goes over subpar roads. He just stopped *actively* noticing it eventually. His rationale was that the suspension is fantastic, but not unbelievable enough that it's able to completely negate the bumps (which, in lesser cars, would be felt as such) on bad roads, and instead turns them into smallish 'jitters'. Our roads can be pretty uneven in places, so I saw some sense in his explanation.

happyinva.

Would definitely check tire/wheel assemblies on a road force machine.Can come less than good from factory.Balance to grams and get road force numbers below 15.If this can be accomplished there should be no tire induced vibration.