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


Go Back   ZPOST > BMW Z4 Technical Talk > Wheels and Tires
  TireRack

SUPPORT ZPOST BY DOING YOUR TIRERACK SHOPPING FROM THIS BANNER, THANKS!
Post Reply
 
Thread Tools Search this Thread
      04-30-2013, 05:41 AM   #1
Messiah9000
Registered
0
Rep
4
Posts

Drives: Z4 Coupe 3.0si Manual M-Pack
Join Date: Apr 2013
Location: Estonia

iTrader: (0)

M-size tires on 3.0si coupe

Hello,

I am planning to buy new tires for my 3.0si coupe (Vredestein Ultrac Sessanta is on my shortlist). I our country there are lot of rough roads and potholes etc. So with my current factory spec RFT Bridgestones the ride is awful - tramlining, nervous, unstable, harsh, high noise etc. I want to go one hight level up, that means M-size tires. Stock 18 inch is front 225/40 and rear 255/35 and I want to go front 225/45 and rear 255/40. I have stock 18 inch wheels, 8 front and 8.5 rear. Has anyone tried M tire sizes with stock wheels? Comments I've read in different forums are not conclusive, some say rear will rub, some say it fits and drives fine.

Second question is that is there any tire manufacturers that make M-tire sizes without XL load marking? Sessanta is XL only. XL means higher load capacity and therefore stiffer sidewall. Stiffer sidewall means more tramlining and harsher ride. I've read a lot about tires the past few days and most folks say that Sessanta is the quietest and softest tire with XL marking. But does any manufacturer make this size without XL?

Thank you in advance!
Appreciate 0
      04-30-2013, 06:07 AM   #2
dubsesd
#dubspec
dubsesd's Avatar
No_Country
6317
Rep
5,200
Posts

Drives: G05 X5/ 2016 F80 M3 INDVL
Join Date: Jul 2011
Location: Ottawa

iTrader: (2)

Buy hankook v12. Soft sidewall comfortable tire
__________________
LCI ///F80 M3 Individual Atlantis Metallic / Black Full / Carbon Cermics / 6MT
MPE / M Performance & Carbon package / KW v3 / 20" HRE R101LW / 20" HRE 527s / Michelin PSS / 20% tint / 3d Design / Streckenn splitters / OEM GTS hood / EAS Carbon seatbacks / Carbon RKP sideskirt / Bootmod3 / M Performance Tri color alcantara / AWE S Flow
instagram: @ dubsesd
Appreciate 0
      04-30-2013, 08:14 AM   #3
v3.2mc
Not a New Member
v3.2mc's Avatar
United_States
94
Rep
925
Posts

Drives: with both hands and both feet
Join Date: Mar 2012
Location: midwest

iTrader: (4)

Garage List
2007 ///M Coupé  [10.00]
they should fit just fine, but acceleration and fuel economy will suffer.
__________________
#1498E86 | Sepang Bronze | Dark Sepang Leather | Carbon Leather Trim
Appreciate 0
      04-30-2013, 08:17 AM   #4
mhughett
Captain
25
Rep
615
Posts

Drives: 2007 Z4 M Coupe
Join Date: May 2009
Location: Tulsa, Ok

iTrader: (0)

I did exactly what you are talking about when I had my 3.0si coupe. I was sick of the RFT's and wanted to change to regular tires. Bought M-sized tires which were slightly (very) taller. In fact, I bought the Hankook V12's. No issues at all with rubbing. Bonus was that the taller tires actually made the speedometer MORE accurate than before. BMW traditionally sets these to read a few mph's faster than you are really going. It was almost dead on after the tire change.
__________________
2013 Audi TT RS (Tech Pkg, Sport Exhaust, Heated Seats, Sirius)

Retired--2007 Z4 M Coupe (Imola Red/Black, Premium Pkg, Heated Seats, XM, Bimmian stubby antenna, CDV delete, Apex EC-7--Anthracite, Goodyear F1 Asymetric 2.
Appreciate 0
      04-30-2013, 08:19 AM   #5
DRedman45
Lieutenant
DRedman45's Avatar
35
Rep
441
Posts

Drives: E86 //M coupe
Join Date: Oct 2012
Location: Northern va

iTrader: (0)

it should fit....but your rough ride issue is more of a run flat problem than a small sidewall problem....like others said, fuel economy will change, and your speedometer will change
Appreciate 0
      04-30-2013, 09:53 AM   #6
mhughett
Captain
25
Rep
615
Posts

Drives: 2007 Z4 M Coupe
Join Date: May 2009
Location: Tulsa, Ok

iTrader: (0)

I did not notice any increase or decrease in fuel economy. This is a VERY small change in the O.D. of the tire. If anything, I would have expected to see an increase in mileage since the O.D. is increasing.
__________________
2013 Audi TT RS (Tech Pkg, Sport Exhaust, Heated Seats, Sirius)

Retired--2007 Z4 M Coupe (Imola Red/Black, Premium Pkg, Heated Seats, XM, Bimmian stubby antenna, CDV delete, Apex EC-7--Anthracite, Goodyear F1 Asymetric 2.
Appreciate 0
      04-30-2013, 06:33 PM   #7
v3.2mc
Not a New Member
v3.2mc's Avatar
United_States
94
Rep
925
Posts

Drives: with both hands and both feet
Join Date: Mar 2012
Location: midwest

iTrader: (4)

Garage List
2007 ///M Coupé  [10.00]
a change of over 4% in diameter is a large difference when comparing performance of tires in relation to engine and chassis dynamics.

as far as fuel economy is concerned, increased diameter will not only change the overall rear end gearing so that more fuel is required to get to X speed at Y time compared the smaller diameter, but it also increases rotational inertia which creates acceleration and deceleration issues. it's possible (though I believe highly unlikely) to over-lever the rear brakes on the non-///m due to the substantially smaller rotor size when paired with too tall of a tire.

if the car is being tracked, I personally would not consider this move. instead, consider a 235/40r18 front and 265/35r18 rear.
__________________
#1498E86 | Sepang Bronze | Dark Sepang Leather | Carbon Leather Trim
Appreciate 0
      05-01-2013, 04:26 PM   #8
ANUSTART
Captain
ANUSTART's Avatar
35
Rep
956
Posts

Drives: Z4
Join Date: Oct 2010
Location: IL

iTrader: (0)

Just ditch the RTFs. I did and all those issues you mentioned went away. Much, much better ride. Your rear could rub and you may need to do a fender roll to accommodate it.
Appreciate 0
      05-02-2013, 08:50 AM   #9
Messiah9000
Registered
0
Rep
4
Posts

Drives: Z4 Coupe 3.0si Manual M-Pack
Join Date: Apr 2013
Location: Estonia

iTrader: (0)

Thank you all for your help! I will stay with stock size and buy Michelin tires. I'm checking PS2, PS3 and PSS for prices and decide between those three. Which is the softest and quietest?
Appreciate 0
      05-02-2013, 08:55 AM   #10
DRedman45
Lieutenant
DRedman45's Avatar
35
Rep
441
Posts

Drives: E86 //M coupe
Join Date: Oct 2012
Location: Northern va

iTrader: (0)

they are all relatively equal on those terms...the pss are obviously the best performing, and maintain the comfort aspect as well
Appreciate 0
      05-02-2013, 08:57 AM   #11
v3.2mc
Not a New Member
v3.2mc's Avatar
United_States
94
Rep
925
Posts

Drives: with both hands and both feet
Join Date: Mar 2012
Location: midwest

iTrader: (4)

Garage List
2007 ///M Coupé  [10.00]
^ +1
__________________
#1498E86 | Sepang Bronze | Dark Sepang Leather | Carbon Leather Trim
Appreciate 0
      05-02-2013, 02:36 PM   #12
ANUSTART
Captain
ANUSTART's Avatar
35
Rep
956
Posts

Drives: Z4
Join Date: Oct 2010
Location: IL

iTrader: (0)

One more for the PSS. Mine are great.
Appreciate 0
      05-06-2013, 07:31 AM   #13
Messiah9000
Registered
0
Rep
4
Posts

Drives: Z4 Coupe 3.0si Manual M-Pack
Join Date: Apr 2013
Location: Estonia

iTrader: (0)

In our country I cant get 255/35R18 rear supersports only ps3. Does anyone have experience running 265/35R18 tire on a stock 8.5 rim?
Appreciate 0
      05-06-2013, 07:54 AM   #14
v3.2mc
Not a New Member
v3.2mc's Avatar
United_States
94
Rep
925
Posts

Drives: with both hands and both feet
Join Date: Mar 2012
Location: midwest

iTrader: (4)

Garage List
2007 ///M Coupé  [10.00]
Quote:
Originally Posted by Messiah9000 View Post
In our country I cant get 255/35R18 rear supersports only ps3. Does anyone have experience running 265/35R18 tire on a stock 8.5 rim?
here, post #62
__________________
#1498E86 | Sepang Bronze | Dark Sepang Leather | Carbon Leather Trim
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 07:18 AM.




zpost
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