Bimmerpost
3
/
4 Series
BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read
Technical Topics Suspension / Chassis / Brakes Is the suspension different for cars equipped with run flats vs. those without?

Post Reply
 
Thread Tools Search this Thread
      12-03-2018, 05:14 AM   #1
cdgatti
Colonel
cdgatti's Avatar
254
Rep
2,547
Posts

Drives: e90 328i
Join Date: May 2011
Location: KY

iTrader: (4)

Is the suspension different for cars equipped with run flats vs. those without?

I see in the spec sheets for the new car that getting run flats or non-run flats will remain an option. Has anyone read whether some suspension components will be different to accommodate the different tires?
__________________
OEM Black grill and Blackline tails - LCI halogens with Lux V2 coded as DRL - 3M Crystalline - BMS PBX - OEM Euro Airbox with K&N - Hardwired CTEK - Bilstein B6 w/OEM springs and SP perches - Conti DWS06 - HiFi-Helix DSP - JLAudio HD/XD-Morel - CD changer trim - AE optical out
Appreciate 0
      12-03-2018, 06:53 AM   #2
mathys
First Lieutenant
mathys's Avatar
No_Country
197
Rep
313
Posts

Drives: G82 - G01 - F56
Join Date: Sep 2011
Location: Netherlands

iTrader: (0)

I have not seen the specs, but I highly doubt they would change the suspension components. Take the non-run flats.
Appreciate 1
      12-04-2018, 01:43 AM   #3
brissim
Lieutenant
84
Rep
510
Posts

Drives: X3 30d (2011 F25) - now sold
Join Date: Jul 2011
Location: Brisbane, Australia

iTrader: (0)

I would very much doubt BMW would set up a different suspensions for vehicles ordered with non-runflat tyres. Overall it would represent a small fraction of its total worldwide sales and wouldn't be worth the engineering effort.

Plus what would happen in the scenario of someone switching from original non-runflats to runflats.

Tony
Appreciate 0
      12-04-2018, 04:14 AM   #4
HighlandPete
Lieutenant General
6659
Rep
15,858
Posts

Drives: BMW F11 535i Touring
Join Date: Mar 2007
Location: Scotland, Highland Region

iTrader: (0)

Quote:
Originally Posted by cdgatti View Post
I see in the spec sheets for the new car that getting run flats or non-run flats will remain an option. Has anyone read whether some suspension components will be different to accommodate the different tires?
I see where you are coming from, would appear to be necessary in the fine tuning of suspension/tires. But no chance of different settings/calibrations, IMO. Years ago RFTs were so different in characteristics to standard non run-flat tires, we could feel a big difference in driving characteristics when we changed tire type. Tire characteristics are not as extreme these days, with vertical stiffness being much closer to each other.

Think about it this way, BMW do not change suspension calibrations for different wheel size options. BMW setup the chassis for the standard fit wheel size. I'd wager changing from 18" to 20" rims will be as big a change, (maybe more) as comparing a run-flat to a non run-flat of the same size.
Appreciate 0
      12-04-2018, 05:09 AM   #5
cdgatti
Colonel
cdgatti's Avatar
254
Rep
2,547
Posts

Drives: e90 328i
Join Date: May 2011
Location: KY

iTrader: (4)

Thanks Pete - yea that makes sense, I hadn't considered the closing of the difference between the two tire types. Just know the E90 used softer rubber bushings in places due to the hard tires.
__________________
OEM Black grill and Blackline tails - LCI halogens with Lux V2 coded as DRL - 3M Crystalline - BMS PBX - OEM Euro Airbox with K&N - Hardwired CTEK - Bilstein B6 w/OEM springs and SP perches - Conti DWS06 - HiFi-Helix DSP - JLAudio HD/XD-Morel - CD changer trim - AE optical out
Appreciate 0
      12-04-2018, 02:58 PM   #6
alex2364
Colonel
alex2364's Avatar
2847
Rep
2,740
Posts

Drives: 2020 M4 ZCP / 2023 X3 M40i
Join Date: May 2005
Location: Northern VA

iTrader: (2)

Garage List
2020 BMW M4  [10.00]
2023 BMW X3 M40i  [10.00]
Only thing I know of is that all season tires get a lower top speed limit.
Appreciate 0
      12-04-2018, 08:36 PM   #7
cdgatti
Colonel
cdgatti's Avatar
254
Rep
2,547
Posts

Drives: e90 328i
Join Date: May 2011
Location: KY

iTrader: (4)

how often do we go 130 and find ourselves needing to go faster up to 155???
__________________
OEM Black grill and Blackline tails - LCI halogens with Lux V2 coded as DRL - 3M Crystalline - BMS PBX - OEM Euro Airbox with K&N - Hardwired CTEK - Bilstein B6 w/OEM springs and SP perches - Conti DWS06 - HiFi-Helix DSP - JLAudio HD/XD-Morel - CD changer trim - AE optical out
Appreciate 0
      12-04-2018, 09:04 PM   #8
alex2364
Colonel
alex2364's Avatar
2847
Rep
2,740
Posts

Drives: 2020 M4 ZCP / 2023 X3 M40i
Join Date: May 2005
Location: Northern VA

iTrader: (2)

Garage List
2020 BMW M4  [10.00]
2023 BMW X3 M40i  [10.00]
Some people care especially you’re going to the track.
Appreciate 0
      12-05-2018, 03:59 AM   #9
hans007
Major
605
Rep
1,077
Posts

Drives: 2020 BMW M340i
Join Date: Aug 2012
Location: Los Angeles, CA

iTrader: (0)

Quote:
Originally Posted by cdgatti View Post
how often do we go 130 and find ourselves needing to go faster up to 155???
its not that. When I had my f30.... the performance summers it came with were much much stiffer than sport non run flats I eventually switched to. can't really get away with it if they are runflats, they will have stiff sidewalls to be able to keep riding if there is a flat.


Its not gonna make a difference going up to 150mph. Its for just every little crack and pothole in the road.

On the G20 it seems you have to get a m340i or a 330i with the dynamic handling package (diff/adaptive suspension etc) to be allowed to get non run flats. But at least you can get the donut with any car, and just swap out you tires after they wear out now
Appreciate 0
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 09:29 AM.




g20
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST