Tirerack
Use the following links to go directly to useful tirerack winter items: Tirerack Winter Tires. Gary's Winter Tire FAQ.
Using the links directly supports E90Post with tirerack sales commision!

  E90Post
 


TireRack

   PLEASE HELP SUPPORT E90POST BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER, THANKS!
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Technical Forums > Wheels and Tires Forum Sponsored by The Tire Rack > Smoother w/ non-runflat's



Wheels and Tires forum Sponsored by The Tire Rack
Please help to directly support e90post by doing your tirerack shopping from the above link. For every sale made through the link, e90post gets sponsor support to keep the site alive. Disclaimer

Wheel offset calculator courtesy of BimmerPost.com. You may use this calculator to calculate what tire sizes you might need if you upgrade your tires, or what wheel sizes/offsets are compatible with your car.
    Current Wheel Width  inches             Current Wheel Offset  mm.
         New Wheel Width  inches                  New Wheel Offset  mm.
 
TIRE WIDTH
/
ASPECT RATIO
- WHEEL DIAMETER
ORIGINAL TIRES
/
NEW TIRES
/
Based on your stock wheel setup, your new wheel will have:
Original Tires Diameter (in.)
      New Tires Diameter (in.)
  Difference in diameter (in.)
           Percent Difference %
                     
Speedo @60mph will read: mph
Collapse/Expand the BimmerPost Wheel and Tire calculator
Reply
 
Thread Tools Search this Thread
      07-22-2005, 12:19 PM   #1
BMRu4ia
Private First Class
 
Drives: 2013 X3 28i VR
Join Date: May 2005
Location: Foster City

Posts: 182
iTrader: (0)

How much smoother w/ non-runflat's??

Could I assume that if my e90 was equiped with non-RF that if would be a smoother ride?
Or is the difference not that noticeable.

Last edited by BMRu4ia; 07-22-2005 at 12:53 PM.
BMRu4ia is offline  
0
Reply With Quote
      07-22-2005, 04:12 PM   #2
CC 330i
Captain
 
CC 330i's Avatar
 
Drives: 330i SG/Blk/Alum
Join Date: May 2005
Location: Orange County, CA

Posts: 722
iTrader: (0)

Quote:
Originally Posted by BMRu4ia
Could I assume that if my e90 was equiped with non-RF that if would be a smoother ride?
Or is the difference not that noticeable.
It's really hard to say. One person said that they didn't notice any adverse effects from going to 19s with non run-flats. Run flats are heavier by up to 10 pounds per tire (from what I have heard) so it stands to reason that less unsprung weight would make for a better ride.

But being that the suspension in the E90 is apparently tuned with run-flats in mind, it's hard to say what a lighter wheel/tire combo would do. I know that the ride on the E90 with run-flats is much better than it is in the Mini and the 5 series with run-flats.

Conventional wisdom is that less unsprung weight will definitely help the ride.
CC 330i is offline  
0
Reply With Quote
      07-22-2005, 04:27 PM   #3
onesixeight
Lieutenant
 
Drives: E92 M3
Join Date: May 2005
Location: Seattle, WA

Posts: 407
iTrader: (0)

I would believe it would be reasonable to assume that if you have two E90s (one with and one without RFT), the non-RFT shod car would ride better than the RFT car. As far as being noticeable, it would really depend how sensitive you are. The E90 non-sport rides very well, and I don't really sense a sense of harshness when going over sharp bumps and railroad tracks.
onesixeight is offline  
0
Reply With Quote
      07-22-2005, 09:24 PM   #4
pondermatic
New Member
 
pondermatic's Avatar
 
Drives: 1986 BMW 535i
Join Date: Mar 2005
Location: Texas

Posts: 5
iTrader: (0)

Quote:
Originally Posted by CC 330i
Run flats are heavier by up to 10 pounds per tire (from what I have heard) so it stands to reason that less unsprung weight would make for a better ride.
According to Tire Rack's specs on the Bridgestone Pontenza RE050A in a 225/45R17 size, the run flat version is 27 lbs. and the regular version is 24 lbs. That's enough to make a small difference in handling, but I'm guessing the bigger factor is the sidewall stiffness.
pondermatic is offline  
0
Reply With Quote
      07-22-2005, 11:56 PM   #5
bzzbenz
First Lieutenant
 
bzzbenz's Avatar
 
Drives: 2011 E93
Join Date: Apr 2005
Location: Orange County

Posts: 368
iTrader: (0)

Send a message via AIM to bzzbenz
Quote:
Originally Posted by BMRu4ia
Could I assume that if my e90 was equiped with non-RF that if would be a smoother ride?
Or is the difference not that noticeable.
I was wondering the same thing today... better ride with out RFT?
__________________
| 2006 325i | Jet Black | Black ette | 6spd manual| Nav | Xenon | Burl | Chrome Tips | 545 sport wheels | Blacklines|
|DOB 6/2/05|Delivered 7/14/05 |
bzzbenz is offline  
0
Reply With Quote
      07-23-2005, 01:04 AM   #6
NaTuReB0Y
Powered By 36DD
 
NaTuReB0Y's Avatar
 
Drives: 2006 E90
Join Date: Jul 2005
Location: Inland Empire

Posts: 7,381
iTrader: (12)

I can guranteed one thing...the non-RF tires are a lot cheaper!
__________________
2006 E90 330i Jet Black | 20" WORK VS-XX | FK452 | H&R Sport on Koni Yellow | REMUS QUAD
NaTuReB0Y is offline   United_States
0
Reply With Quote
      07-24-2005, 08:42 AM   #7
coco
Second Lieutenant
 
coco's Avatar
 
Drives: Bimmmer
Join Date: Jun 2005
Location: Texas

Posts: 284
iTrader: (0)

Quote:
Originally Posted by CC 330i
It's really hard to say. One person said that they didn't notice any adverse effects from going to 19s with non run-flats. Run flats are heavier by up to 10 pounds per tire (from what I have heard) so it stands to reason that less unsprung weight would make for a better ride.

But being that the suspension in the E90 is apparently tuned with run-flats in mind, it's hard to say what a lighter wheel/tire combo would do. I know that the ride on the E90 with run-flats is much better than it is in the Mini and the 5 series with run-flats.

Conventional wisdom is that less unsprung weight will definitely help the ride.
Holy crap, are they really heavier by up to 10 pounds each?? I'm definitely switching to non-runflats when these stock tires are done. 10 pounds at each corner will make such an awesome difference in handling. I guarantee it.

Also, altho I don't have specific experience with using non-runflats on this car, on paper the non-runflats must ride more comfortablly / less harsh than the runflats because the runflats have a much much stiffer sidewall.
coco is offline  
0
Reply With Quote
      07-24-2005, 09:25 AM   #8
stressdoc
Moderator
 
stressdoc's Avatar
 
Drives: 335 E90 ZSP+
Join Date: Jun 2005
Location: MO

Posts: 9,905
iTrader: (0)

Pondermatic provides the data (thanks!): 27 lbs. runflat vs. 24 lbs regular, i.e., 3 lbs. difference. That is within the range of variation of regular tires. 3 lbs. will not affect ride quality in most circumstances. Unsprung weight is important for handling over rough surfaces, that is, situations in which the wheel assembly is moving up and down. The lighter the wheel assembly, the easier it is to control the movement, it has less momentum. This is especially important for off-road motorcycles, desert racing, rallye cars and the like. It is not as big a deal for luxury cars on the street. I guarantee Cadillacs have more unsprung weight than an E90. It is the sidewall stiffness, as Pondermatic states, that is the relevant variable affecting ride quality, i.e., the extent to which we can 'feel' bumps. If you want a smoother ride, get higher aspect tires (e.g., switch to a 60 series) that are designed for ride quality. The tradoff is that the tire will 'bend' more during sideways loads, hence will not corner as well. I prefer the go-kart feel. When we are down to 30 aspect ratio tires, the difference btw a regular and a non-flat is almost imperceptible. At this point we need to assess which tire performs. Anyone know of any good runflat comparison tests yet?
stressdoc is offline   Dominica
0
Reply With Quote
      07-24-2005, 02:01 PM   #9
cypwood
Private
 
Drives: BMW 330 I 2006
Join Date: Jul 2005
Location: South Florida

Posts: 56
iTrader: (0)

Run Flat Tires

Can you order Michelin Pilot Sport tires at the same time you order your car ? -- Or is it at crap shoot. ? Plan to order a 330 I.

Thanks,
Donnie
cypwood is offline  
0
Reply With Quote
      07-24-2005, 04:12 PM   #10
onesixeight
Lieutenant
 
Drives: E92 M3
Join Date: May 2005
Location: Seattle, WA

Posts: 407
iTrader: (0)

Quote:
Originally Posted by cypwood
Can you order Michelin Pilot Sport tires at the same time you order your car ? -- Or is it at crap shoot. ? Plan to order a 330 I.

Thanks,
Donnie
It's pretty much a crap shoot...My car came with Pirellis and I wanted the Bridgestones...They made a swap for me with another car.
onesixeight is offline  
0
Reply With Quote
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
Forum Jump


All times are GMT -5. The time now is 09:48 AM.




e90post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
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