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 > Tire pressures...the definitive answer?



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
      12-10-2007, 10:26 AM   #1
gobo335i
Toy Wrangler
 
gobo335i's Avatar
 
Drives: 135i - GoCart on Steroids
Join Date: May 2007
Location: Los Angeles, California

Posts: 193
iTrader: (0)

Tire pressures...the definitive answer?

I run 19" CSL's on Excta Rubber and am not finding definitive answers to tire pressure.

On the forums I see 35psi F and 38psi R, I see 40psi F and 44psi R....

I looked at my brothers 2005 M3 with CSL's and his car says to run 41psi F and 48psi R!

I hear on a track the best is to run 35psi F&R cold and adjust to 40psi after the tires are nice and hot.

So whats the call? Are all tires different? Is this a case of "adjust till they feel right"? Does the European model on 19" without RFT's have specs to follow?

I am running 41psi F and 46psi R currently as the max pressure is rated at 50psi for all.

I know...I searched. After finding so many different answers, I was hoping an authority would offer some help.

Note, I am searching for pressures for running hard on the street and twisties, not drag racing.

Thanks!
__________________
Had a 335i. It was a highway missile. Traded to a 135i. It's a go-cart on steroids.
gobo335i is offline   United_States
0
Reply With Quote
      12-10-2007, 12:20 PM   #2
giddyup69
Private First Class
 
Drives: '13 F30 335xi
Join Date: Nov 2007
Location: Toronto, On, Canada

Posts: 156
iTrader: (1)

why wouldn't you just follow the specs from bmw?
Attached Images
 
giddyup69 is offline   Canada
0
Reply With Quote
      12-10-2007, 12:44 PM   #3
gobo335i
Toy Wrangler
 
gobo335i's Avatar
 
Drives: 135i - GoCart on Steroids
Join Date: May 2007
Location: Los Angeles, California

Posts: 193
iTrader: (0)

Now why would someone want to do a thing like that?

From the manual huh. I read the thing cover to cover and don't remember seeing a chart that included my tire sizes.

Nice.
__________________
Had a 335i. It was a highway missile. Traded to a 135i. It's a go-cart on steroids.
gobo335i is offline   United_States
0
Reply With Quote
      12-10-2007, 01:08 PM   #4
E92Fan
Moderator
 
E92Fan's Avatar
 
Drives: .
Join Date: Aug 2007
Location: .

Posts: 5,492
iTrader: (0)

Wait - the BMW chart assumes you're using runflats.

If you're on non-RFTs, consider using the Alpina settings on 19" wheels - 2.6bar at the front, 2.7bar at the back (37psi, 39psi)
E92Fan is offline   United Kingdom
0
Reply With Quote
      12-10-2007, 03:50 PM   #5
montreal_bimmer
Major General
 
montreal_bimmer's Avatar
 
Drives: E90 AW
Join Date: Feb 2006
Location: Montreal

Posts: 5,501
iTrader: (6)

Garage List
2006 325i  [5.00]
i've heard that there is a bit of an advantage in handling with going with slightly more pressure up front than in the rear... if i'm not mistaken, BMW.WillimsF1 team was doing this in 2003, when they came close to winning a championship....
montreal_bimmer is offline   Italy
0
Reply With Quote
      12-08-2008, 06:20 PM   #6
E90330iS
Major General
 
Drives: E90 330i
Join Date: Jan 2006
Location: Redwood City, California

Posts: 6,300
iTrader: (55)

Garage List
2006 330i  [0.00]
Send a message via AIM to E90330iS Send a message via MSN to E90330iS Send a message via Skype™ to E90330iS
41/49 too much for 19" wheels?
__________________
Moved to the Bay Area. Looking for meets!
E90330iS is offline   Germany
0
Reply With Quote
      12-08-2008, 09:02 PM   #7
John 070
Lieutenant General
 
Drives: 335i cpe
Join Date: Oct 2006
Location: ZSP/ZPP/ZCW

Posts: 11,236
iTrader: (0)

Quote:
Originally Posted by giddyup69 View Post
why wouldn't you just follow the specs from bmw?
I'm with you. Instead of 35/32, BMW could say 40/37, and people would still add 5-6 lbs. because BMW obviously underestimates their numbers....
John 070 is offline  
0
Reply With Quote
      12-08-2008, 11:00 PM   #8
gobo335i
Toy Wrangler
 
gobo335i's Avatar
 
Drives: 135i - GoCart on Steroids
Join Date: May 2007
Location: Los Angeles, California

Posts: 193
iTrader: (0)

tire pressures

I was told by a professional that you add 2lbs for every inch over the 'stock size' your tires are. Therefore, if your door sticker says 35 front and 34 rear, and you had 'stock' 18's, and now 19's, your pressures would be 37 and 36 respectively. Using this method, my 19's and tires have worked perfectly and worn perfectly for 25,000 miles. I am content that this is a good method.

Of course, if you go to a track, then this is all out the door as the tires heat up way more than they ever would on the street. In that case I would start lower and let them heat up. Or use nitrogen
__________________
Had a 335i. It was a highway missile. Traded to a 135i. It's a go-cart on steroids.
gobo335i is offline   United_States
0
Reply With Quote
      12-09-2008, 07:33 PM   #9
Dan335i
Lieutenant Colonel
 
Dan335i's Avatar
 
Drives: 07 335i coupe 6MT,w/sp. pack.
Join Date: Oct 2007
Location: orange county NY

Posts: 1,788
iTrader: (2)

My 07 335i coupe with sport package (189 w/REOA50 rft) says in the door to run 32ft and 35 rear.I run 34 and 37 and it feels much better all around driving.
Dan335i 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 03:24 PM.




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