BMW M3 Forum (E90 E92)

BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > Wheels + Tires Sponsored by The Tire Rack
  TireRack

KEEP M3POST ALIVE BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER LINK!
Post Reply
 
Thread Tools Search this Thread
      11-11-2013, 02:22 PM   #1
Superfly_M3
Captain
 
Drives: 2011 M3
Join Date: Sep 2011
Location: Toronto

Posts: 964
iTrader: (0)

Winter Tire Question

I currently have OEM BMW winter package setup:
Style 270, 18x8 ET 20 with 235/40/18 Michelins Pilot Alpins. No spacers. Oddly, there is no threadwear indicator on the OEM tires

The speedometer is affected by "a lot" at 135km/h indicated on the speedo, GPS confirms the speed to be at 125km/h. The tire diameter is 25.40"

Original front 245/35/19 are 25.47" and rears 265/35/19 are 26.30"

My back tires are "gone" and need replacements. I was wondering if anyone ran 245/45/18 in the back (26.68") and 245/40/18 in the front (25.71")
Because my car is lowered, the extra clearance is a good thing in the winter.
Can the 18x8 rim fit a 245 series tire?

Thanks in advance
Superfly_M3 is offline  
0
Reply With Quote
      11-11-2013, 03:05 PM   #2
BMW Fanatic
Banned
 
Drives: slow
Join Date: Jul 2009
Location: Calgary

Posts: 3,314
iTrader: (11)

Yes. 245/40/18 is what I ran the last 2 winters on an 18x8 square set-up. This year I'm running OEM 219's (8.5F, 9.5R) with 255/40/18 square tire set up. You'll be fine.

EDIT: Don't run a 245/45. Lol.
BMW Fanatic is offline   Canada
0
Reply With Quote
      11-11-2013, 03:42 PM   #3
Superfly_M3
Captain
 
Drives: 2011 M3
Join Date: Sep 2011
Location: Toronto

Posts: 964
iTrader: (0)

Thanks for the reply,
Why no 245/45/18?
Superfly_M3 is offline  
0
Reply With Quote
      11-12-2013, 05:22 PM   #4
ben@tirerack
M3Post Supporting Vendor
 
Drives: 740i
Join Date: Mar 2008
Location: South Bend, IN

Posts: 823
iTrader: (0)

245/45R18 fits an 18x8 wheel, and would probably be fine on the rear.

But it is a lot easier to have all 4 tires the same. You will have more tire choices because you don't have to hunt for matching front/rear pairs. You will be able to rotate so that they wear out at the same time.

Regarding ground clearance: I doubt the extra fraction of an inch of ground clearance at the rear will give you any realistic benefit in deep snow. If you've already pushed your front aero through the snow, you're not likely to get the rear end hung up.

Regarding speedometer, the factory calibration is a big part of the reason you are noticing so much difference. Looking at some math:

26.3/25.4 = 1.035 ~3.5% error from tires
135/125 = 1.08 ~8% error observed.

Tire error is 3.5%, speedo error is 8% Just over half of the error is built in.
__________________
_______________________________________________



To credit the forum, click through one of the banners in my signature and the top of the page, or call me direct at 877.522.8473 ext 660.
Email:ben@tirerack.com
ben@tirerack is offline  
0
Reply With Quote
      11-19-2013, 12:13 PM   #5
WarrantyTracker
Track? What Track? I was just riding along . . .
 
Drives: Alpine White E92 M3
Join Date: Apr 2012
Location: An Undisclosed Location

Posts: 534
iTrader: (0)

I like "square" snow setups. The tires are soft and the rears wear crazy fast, especially if you live somewhere that the temps bounce and you get a few warm days every winter month. With squares you can rotate.
WarrantyTracker is offline   United_States
0
Reply With Quote
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
Forum Jump


All times are GMT -5. The time now is 08:26 AM.




m3post
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