Very Harsh Ride Quality in M/S

[Cyclone]

Indeed even after adjusting the hatch bumpers, the boom resulting from the (I assume) combination of stiff frame incl battery, and the light, open body structure can be annoying. I measure 84 db at 70mph on my daily drive, compared to 80db for the Range Rover diesel it replaced. So, yes, even though there's no engine noise, the boominess makes it louder while cruising compared to likely any luxury ICE.

I've noticed a huge difference when I have my parcel shelf out or up when transporting cargo. Do you have the parcel shelf in place and the seats up?

 

[vgrinshpun]

What?! That's waaay too high.
Lower your tire pressure to 40psi, and you'll notice a night and day difference. Money-back guarantee.
I have staggered 21" rims, at 40/42psi, and the ride is creamy and comfy.
Good luck.

Manufacturer recommended pressure for 19 inch wheels is 45psi. Running lower pressure especially by 5psi will create risk of blowout either due to heat buildup for high speed driving or road hazard impact.

The pressure recommendation for 21" wheels is different - for my staggered setup it is 38psi front, 40psi rear.

 

[oktane]

Manufacturer recommended pressure for 19 inch wheels is 45psi. Running lower pressure especially by 5psi will create risk of blowout either due to heat buildup for high speed driving or road hazard impact.

The pressure recommendation for 21" wheels is different - for my staggered setup it is 38psi front, 40psi rear.

I doubt that, I think the higher pressure is mainly for less rolling resistance. I thought about deflating my tires too but would probably result in dashboard warnings.

 

[vgrinshpun]

I doubt that, I think the higher pressure is mainly for less rolling resistance. I thought about deflating my tires too but would probably result in dashboard warnings.

Well I suggest you study this issue if you do not believe me. Under inflated tires run much hotter, wearing the thread much faster, and exposing the tire to undue risk from the heat buildup and much lower threshold to damage from road hazard impacts.

 

[12Pack]

I've noticed a huge difference when I have my parcel shelf out or up when transporting cargo. Do you have the parcel shelf in place and the seats up?

Thanks for the tip. Do you mean less "boom" without the parcel shelf - or more? In any case will give it a try without the parcel shelf.

 

[oktane]

Well I suggest you study this issue if you do not believe me. Under inflated tires run much hotter, wearing the thread much faster, and exposing the tire to undue risk from the heat buildup and much lower threshold to damage from road hazard impacts.

Are you saying that every other car on 19 inch wheels not inflated to 45 mph will experience some sort of accident? I’ve owned many cars over the years with 19 inch wheels and similar size tires that are not inflated to 45 psi because it is too harsh. You do realize that 50 psi is often the maximum the tires are rated to...

 

[kort677]

Are you saying that every other car on 19 inch wheels not inflated to 45 mph will experience some sort of accident? I’ve owned many cars over the years with 19 inch wheels and similar size tires that are not inflated to 45 psi because it is too harsh. You do realize that 50 psi is often the maximum the tires are rated to...

I believe that what he is saying is that ANY car riding on severely under inflated tires are more prone to suffering a catastrophic tire failure than running the tires at the recommended levels of inflation.

 

[tccartier]

Are your 19" tires the older GoodYear Eagle RS-A2 ? If so, and they're mid-life or towards the end of life, they could be a source of the harsh ride. Those tires are a High-Performance All-Season, which will not have the ride quality of a better brand and type of tire like the Michelin Primacy MXM4, which is a Grand Touring All-Season tire.

It's also possible that you have aftermarket tires on the car (not likely since it's a CPO, but something I would check). Perhaps someone installed run-flats, which are known to have a very harsh ride.

The tires are 19 in Goodyear Eagle as2 they were installed new about a month ago when I took delivery of the car so they are definitely not worn out they only have about four thousand miles on them.

At the end of the day I think the car is just doing what the car does it's just a harder ride than I'm used to having and that I expected.

 

[Cyclone]

Thanks for the tip. Do you mean less "boom" without the parcel shelf - or more? In any case will give it a try without the parcel shelf.

Without the parcel shelf and/or with the seats down, I get significantly more road noise into the cabin where I can hear it over my music. Kind of like a resonating hum.

 

[lux_cars]

Provably because you’re coming from a Town Car.

Cars keep getting stiffer and stiffer with bigger wheels!! Heck even luxury cars now have options for 21” and you can get 22” wheels on Rolls Royces and Bentleys!

Blame the “Germanification” of cars?

I wonder if OP could install 18” or 17” wheels on their car? That would make a huge difference and also reduce road noise.

 

[SomeJoe7777]

Well I suggest you study this issue if you do not believe me. Under inflated tires run much hotter, wearing the thread much faster, and exposing the tire to undue risk from the heat buildup and much lower threshold to damage from road hazard impacts.

In general this is true, and underinflated tires can indeed be a hazard.

However, the recommended pressure on the door jam is a pressure that is selected by the manufacturer to maintain safety under all conditions that the car is designed for and capable of. i.e. 45 psi on the 19" tires is safe for driving and safe for the tires even when the vehicle is fully loaded to the GVWR rating, and even when the car is travelling at it's maximum speed (140-155 MPH).

If the vehicle is not loaded to the GVWR and/or the vehicle is not travelling at speed, then the tire can still be safe at lower pressures. However, other factors may suffer such as fuel economy or handling/performance.

 

[12Pack]

Back to comments by the OP - its not the road noise I find annoying, but rather the booming resonance of the frame - like a subwoofer playing in the background during a quiet scene in a home theater. Without that I would find the road manners to be quite acceptable. With this resonance, even without engine noise, it is certainly louder than most luxury cars at speed.

 

[cab]

Indeed even after adjusting the hatch bumpers, the boom resulting from the (I assume) combination of stiff frame incl battery, and the light, open body structure can be annoying. I measure 84 db at 70mph on my daily drive, compared to 80db for the Range Rover diesel it replaced. So, yes, even though there's no engine noise, the boominess makes it louder while cruising compared to likely any luxury ICE.

There is a thread here about pressure buffeting. I replaced my center adjusters with a solid rubber dowel, which improves it. Nothing cures it completely (they all do it to some degree, but many people aren't sensitive to it). I'll try to replace the lower adjusters at some point, but they are more hassle.

 

[Sharpgt]

Borrow rent or steal a GTR to drive for a few days. After that you will think your MS rides like a Caddy! Lol

 

[12Pack]

I have a car even stiffer than the GTR for the weekends - and it doesn't have adaptive damping. That's what annyus me - even the V12 Vantage, stiff as it is, doesn't have this low frequency boom over bumps. I'll give adjusting the dampers further another try - I guess I'm now just too sensitive to it.