Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series / 4 Series

3 Series / 4 Series
The 3 Series / 4 Series Forum. If you would like to see all new posts in all the forums, click here.

 
 
Thread Tools Display Modes
  #1  
Old 01-06-2003, 12:52 PM
JPinTO JPinTO is offline
2001 M3:Stick, what else?
Location: Toronto
 
Join Date: Dec 2001
Posts: 3,303
Mein Auto: ///MMMmmm good
M68 Wheel Offset

I've searched everywhere and am getting nowhere.

What is the offset of the OEM M68 17" x 7.5 and 8.5" wheels?
Ads by Google
  #2  
Old 01-06-2003, 12:55 PM
Mr. The Edge's Avatar
Mr. The Edge Mr. The Edge is offline
.
Location: .
 
Join Date: Dec 2001
Posts: 20,241
Mein Auto: .
Hopefully someone knows.

Here are the special M3 M68 specs:

Quote:
There is a special verson of the BMW M68 wheels for the new E46 M3 with
the right offset and clearance for brakes. Fits both US and European cars
and you can get them from any BMW dealer!

36-11-2-229-480 front 7 1/2 x 17 offset 47 mm
36-11-2-229-980 rear 7 1/2 x 17 offset 25 mm

BMW recommends 225/45-17 for winter tires on these rims (to be able to
fit snow chains).

/RS2
__________________
Belief cannot argue with unbelief, it can only preach to it

To clasp the hands in prayer is the beginning of an uprising against the disorder of the world.
  #3  
Old 01-06-2003, 12:57 PM
Nick325xiT 5spd's Avatar
Nick325xiT 5spd Nick325xiT 5spd is offline
Registered User
Location: Bethesda, MD
 
Join Date: Dec 2001
Posts: 10,861
Send a message via ICQ to Nick325xiT 5spd Send a message via AIM to Nick325xiT 5spd Send a message via Yahoo to Nick325xiT 5spd
Mein Auto: M3 & 323i/999 KP
Last I checked, generic 3'er wheels are in the 35-45 range.
__________________
2006 GMC Sierra 2500HD 4WD Duramax LBZ/Allison 6-speed
2002 BMW M3 Alpinweiß/Black
1999 323i KP/GTS2 Alpinweiß
1990 325is Brilliantrot/Tan
1989 325is S50B30US Alpinweiß/Black
1989 M3 Alpinweiß/Black S50B32 (321hp, ITBs)


  #4  
Old 01-06-2003, 01:00 PM
Kaz's Avatar
Kaz Kaz is offline
King of Rear Clunks
Location: OC, CA
 
Join Date: Dec 2001
Posts: 12,915
Mein Auto: 01 325iT, 88 M6
I forget, are offsets cast into the back of the stock wheels?

I'm fairly certain OEM 8" wide wheels are 45 or 47, and 8.5s are upto 50. Of course M3 rears are totally different.
  #5  
Old 01-06-2003, 01:08 PM
JPinTO JPinTO is offline
2001 M3:Stick, what else?
Location: Toronto
 
Join Date: Dec 2001
Posts: 3,303
Mein Auto: ///MMMmmm good
Offsets are on the inside of the wheel.

I just need a confirmed data point:

Here is the likely offsets:

If 8.0" is 47ET, then-- 7.5" is 41ET and 8.5" is 53ET.

Handy calculator:
http://toy4two.home.mindspring.com/offset.html

This would make the E46 & M3E46 the exact same wheel spec for the FRONTS.

The Rears are different. A 8.5" M68 on the rear of an M3 would require 33mm spacer to get them to the correct spot.

Last edited by JPinTO; 01-06-2003 at 01:10 PM.
  #6  
Old 01-06-2003, 01:11 PM
sp330i's Avatar
sp330i sp330i is offline
Be a race car Daddy!
Location: in the sunshine
 
Join Date: Dec 2001
Posts: 326
Send a message via AIM to sp330i
Mein Auto: '01 330i SP, PP
for the 330 sp, here is the correct answer

17 x 7.5 is 41mm

17 x 8.5 is 50mm
  #7  
Old 01-06-2003, 01:13 PM
Kaz's Avatar
Kaz Kaz is offline
King of Rear Clunks
Location: OC, CA
 
Join Date: Dec 2001
Posts: 12,915
Mein Auto: 01 325iT, 88 M6
Quote:
Originally posted by JPinTO

This would make the E46 & M3E46 the exact same wheel spec for the FRONTS.

The Rears are different. A 8.5" M68 on the rear of an M3 would require 33mm spacer to get them to the correct spot.
We already know the M3 fronts are the 'normal' offset.

The rears would require a big enough offset that it might not be a good idea.

The other question is if the M3 brake calipers are bigger (I know the rotors are the same dia but thicker compared to a 330) whether they would fit behind any given non-M3 wheel.

Are you trying to see if M68s will work on a M3?
  #8  
Old 01-06-2003, 01:17 PM
JPinTO JPinTO is offline
2001 M3:Stick, what else?
Location: Toronto
 
Join Date: Dec 2001
Posts: 3,303
Mein Auto: ///MMMmmm good
Re: for the 330 sp, here is the correct answer

Quote:
Originally posted by sp330i
17 x 7.5 is 41mm

17 x 8.5 is 50mm
Thank you.
  #9  
Old 01-06-2003, 01:25 PM
JPinTO JPinTO is offline
2001 M3:Stick, what else?
Location: Toronto
 
Join Date: Dec 2001
Posts: 3,303
Mein Auto: ///MMMmmm good
Quote:
Originally posted by Kaz
We already know the M3 fronts are the 'normal' offset.

The rears would require a big enough offset that it might not be a good idea.

The other question is if the M3 brake calipers are bigger (I know the rotors are the same dia but thicker compared to a 330) whether they would fit behind any given non-M3 wheel.

Are you trying to see if M68s will work on a M3?

Yes... trying to see what will transfer from my 323 to an M3. Why ?

I've read that the brakes will clear 17's. They aren't any larger than the 330s in diameter.

So, if I want to make it work, I'll need a 30mm spacer or a M68 specific to an M3. Didn't even know there were different offset M68s.
  #10  
Old 01-06-2003, 01:26 PM
Mr. The Edge's Avatar
Mr. The Edge Mr. The Edge is offline
.
Location: .
 
Join Date: Dec 2001
Posts: 20,241
Mein Auto: .
Quote:
Originally posted by JPinTO
Offsets are on the inside of the wheel.

I just need a confirmed data point:

Here is the likely offsets:

If 8.0" is 47ET, then-- 7.5" is 41ET and 8.5" is 53ET.


This would make the E46 & M3E46 the exact same wheel spec for the FRONTS.

The Rears are different. A 8.5" M68 on the rear of an M3 would require 33mm spacer to get them to the correct spot.
but the E46M3 M68 has a 47 offset for the fronts, apparently
__________________
Belief cannot argue with unbelief, it can only preach to it

To clasp the hands in prayer is the beginning of an uprising against the disorder of the world.
  #11  
Old 01-06-2003, 01:29 PM
JPinTO JPinTO is offline
2001 M3:Stick, what else?
Location: Toronto
 
Join Date: Dec 2001
Posts: 3,303
Mein Auto: ///MMMmmm good
Quote:
Originally posted by atyclb
but the E46M3 M68 has a 47 offset for the fronts, apparently
But a 8" ET47 will stick out exactly the same as a 7.5" ET41. The tire will of course be narrower, but will fill the wheel well equivalently.

Maybe I'll jam the 8.5"s on the fronts and buy new M3 specific offset M68 for the rear.
  #12  
Old 01-06-2003, 01:30 PM
The HACK's Avatar
The HACK The HACK is offline
Rest in peace, Coach
Location: People's Republic of United States
 
Join Date: Dec 2001
Posts: 9,108
Mein Auto: '06 MZ4C, '09 WRX Wagon
Quote:
Originally posted by atyclb
but the E46M3 M68 has a 47 offset for the fronts, apparently
I thought the working offset would be a range of number...And it probably depend a lot more on TIRE fitment than wheel size.

The 17"x8" wheel/tire combination gets mounted 225/45/17s, as does the 17"x7.5" fronts of the 330i/Ci sports package, right?
__________________
Quote:
"Bench racing" about track times driven by professionals are like a bunch of nerds arguing which Princess Leia is hotter, the slave Leia or the no-bra jail-bait Leia. No matter how compelling your argument is, the plain and simple fact is, none of you will EVER get to hit that.
  #13  
Old 01-06-2003, 01:33 PM
JPinTO JPinTO is offline
2001 M3:Stick, what else?
Location: Toronto
 
Join Date: Dec 2001
Posts: 3,303
Mein Auto: ///MMMmmm good
Quote:
Originally posted by The HACK
I thought the working offset would be a range of number...And it probably depend a lot more on TIRE fitment than wheel size.

The 17"x8" wheel/tire combination gets mounted 225/45/17s, as does the 17"x7.5" fronts of the 330i/Ci sports package, right?
A tire has a range of rim widths that it will fit on. I'm sure a 225 will fit a 7" and as big as an 8.5". (Not that it would look great doing so).

I would imagine that if you stick with the OEM offset numbers, then you can go with wider tires and still clear.
  #14  
Old 01-06-2003, 01:37 PM
Sjumper Sjumper is offline
Angry at the world
Location: Richmond Hill, Ontario, Canada
 
Join Date: Jan 2002
Posts: 429
Mein Auto: 330i
You can "jam" a wheel on with incorrect offset. You might even be lucky enough to not have clearance problems. However, incorrect offset can mean the weight of the car is not correctly distributed on the wheel - leading to vibration problems at higher speeds.

Just something to think about.

I went through hell this past summer when Steelecase ordered incorrect rims for my Subaru Impreza. The offset was wrong and the vibration was awful.

Last edited by Sjumper; 01-06-2003 at 01:39 PM.
  #15  
Old 01-06-2003, 01:38 PM
JPinTO JPinTO is offline
2001 M3:Stick, what else?
Location: Toronto
 
Join Date: Dec 2001
Posts: 3,303
Mein Auto: ///MMMmmm good
Quote:
Originally posted by Sjumper
You can "jam" a wheel on with incorrect offset. You might even be lucky enough to not have clearance problems. However, incorrect offset can mean the weight of the car is not correctly distributed on the wheel - leading to vibration problems at higher speeds.

Just something to think about.
A 30mm H&R Spacer should make the M68 8.5" exactly equivalent to an rear M3 wheel:

  #16  
Old 01-06-2003, 01:50 PM
Kaz's Avatar
Kaz Kaz is offline
King of Rear Clunks
Location: OC, CA
 
Join Date: Dec 2001
Posts: 12,915
Mein Auto: 01 325iT, 88 M6
Depending on how the wheel is designed, a different offset may or may not present clearance problems between the rear face of the wheel and the front face of the caliper.

If the offset (say between the ET41 and ET47) is the difference of 6mm in where the wheel center is mounted (through the spokes) relative to the width of the lip section, then no, a ET41 will not present a (potential) caliper clearance problem.
OTOH, if the offset difference is in the depth of the wheel center's hub interface, a loss of 6mm here may cause the caliper to hit the back face of the wheel without seating on the hub, therefore the wheel will not mount.

If atyclb's note is correct and there is a special ET47 front wheel, the ET41 may be of the latter case, and may not fit. A 6mm spacer would do the job in terms of regaining the caliper clearance but then comes the question of whether or not the new ET35 (effective) wheel+tire will rub the fenderwell someplace.

See, this stuff is NOT trivial.
 

Bookmarks


Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series / 4 Series
Today's Posts Search
Thread Tools
Display Modes

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 On



Forum Jump


All times are GMT -7. The time now is 09:27 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
© 2001-2011 performanceIX, Inc. All Rights Reserved .: guidelines .:. privacy .:. terms