OEM 18" Wheel Q - Pontiac GTO Forum
User Tag List

 
LinkBack Thread Tools Display Modes
post #1 of 10 (permalink) Old 10-08-2012, 10:59 PM Thread Starter
 
Giacobazzi's Avatar
 
Join Date: Aug 2012
Location: Las Vegas NV
Posts: 51
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
OEM 18" Wheel Q

Can someone please tell me the offset and back spacing for the OEM 18" wheel. I can't seem to find this info.

Thanks so much!

Giaco
Giacobazzi is offline  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old 10-09-2012, 07:35 AM
 
AlaGreyGoat's Avatar
 
Join Date: Jul 2006
Location: Birmingport, Alabama
Posts: 827
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
I think the 18s are the same as the stock 17s??
Stock 8" 17s are listed as +48mm offset, but actually measure +50mm with
a 6.47" backspace.

Larry

2005 GTO Quick - 1984 Honda V65 Magna Quicker - 2004 Z06 Quickest
AlaGreyGoat is offline  
post #3 of 10 (permalink) Old 10-09-2012, 09:05 AM Thread Starter
 
Giacobazzi's Avatar
 
Join Date: Aug 2012
Location: Las Vegas NV
Posts: 51
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks Larry! So if I were to go with a +45mm offset wheel, this 2-5mm less of offset would bring my tire out toward the fender lip, or more inward toward the strut? I'm thinking inward.

Giaco

Last edited by Giacobazzi; 10-09-2012 at 09:29 AM.
Giacobazzi is offline  
 
post #4 of 10 (permalink) Old 10-09-2012, 10:00 AM
Former Moderator
 
svede1212's Avatar
 
Join Date: Oct 2005
Location: Grand Rapids, Michigan
Posts: 4,081
Mentioned: 0 Post(s)
Tagged: 1 Thread(s)
Quoted: 25 Post(s)
Garage
Smaller offset is more to the outside with the same width wheel. A few mm wouldn't even be noticeable.

2004 Blk/Rd M6
6.3 litre LS1

Built and tuned by svede
svede1212 is offline  
post #5 of 10 (permalink) Old 10-09-2012, 11:10 AM Thread Starter
 
Giacobazzi's Avatar
 
Join Date: Aug 2012
Location: Las Vegas NV
Posts: 51
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by svede1212 View Post
Smaller offset is more to the outside with the same width wheel. A few mm wouldn't even be noticeable.
Cool! Thank you!

Giaco
Giacobazzi is offline  
post #6 of 10 (permalink) Old 10-10-2012, 07:10 PM
 
AlaGreyGoat's Avatar
 
Join Date: Jul 2006
Location: Birmingport, Alabama
Posts: 827
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
A few mm positive on the front, could make a difference.
On some cars, the stock offset rubs the strut.
On the rear it wouldn't matter.

Larry

2005 GTO Quick - 1984 Honda V65 Magna Quicker - 2004 Z06 Quickest
AlaGreyGoat is offline  
post #7 of 10 (permalink) Old 10-11-2012, 06:20 PM
Former Moderator
 
svede1212's Avatar
 
Join Date: Oct 2005
Location: Grand Rapids, Michigan
Posts: 4,081
Mentioned: 0 Post(s)
Tagged: 1 Thread(s)
Quoted: 25 Post(s)
Garage
Quote:
Originally Posted by AlaGreyGoat View Post
A few mm positive on the front, could make a difference.
On some cars, the stock offset rubs the strut.
On the rear it wouldn't matter.

Larry
Even if it did have more positive offset it would be extremely easy to fix with some ARP wheel studs and a thin wheel spacer. When you widen stock wheels like I did with my rear wheels the extra inch made the offset +61mm (half the total of the addition plus the original 48mm). I brought that back to +56mm with ARPs and 5mm spacers. You can go up to about 7mm and still be sufficiently on the hub. Considerably too small of an offset is much more of a problem.

2004 Blk/Rd M6
6.3 litre LS1

Built and tuned by svede
svede1212 is offline  
post #8 of 10 (permalink) Old 10-11-2012, 08:25 PM
 
AlaGreyGoat's Avatar
 
Join Date: Jul 2006
Location: Birmingport, Alabama
Posts: 827
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 7 Post(s)
^^True, but you need hubcentric spacers, if you exceed about
4mm thick, or the wheel bore won't rest on the hub. Plus, this is about the
max to get a full lug nut on the stock studs.
A spacer over about 4mm needs to be hubcentric to the hub and have
a hubcentric fit to the wheel, also.
Also need longer (and stronger) studs, as svede stated.

Larry

2005 GTO Quick - 1984 Honda V65 Magna Quicker - 2004 Z06 Quickest
AlaGreyGoat is offline  
post #9 of 10 (permalink) Old 10-11-2012, 08:51 PM
Former Moderator
 
svede1212's Avatar
 
Join Date: Oct 2005
Location: Grand Rapids, Michigan
Posts: 4,081
Mentioned: 0 Post(s)
Tagged: 1 Thread(s)
Quoted: 25 Post(s)
Garage
I use a 5mm spacer. There's still plenty of hub. I think it's foolish to not replace the studs regardless. The stock ones are extremely soft and snap easily. Some have snapped them launching the car. I consider it a safety upgrade.

2004 Blk/Rd M6
6.3 litre LS1

Built and tuned by svede
svede1212 is offline  
post #10 of 10 (permalink) Old 10-14-2012, 10:40 AM Thread Starter
 
Giacobazzi's Avatar
 
Join Date: Aug 2012
Location: Las Vegas NV
Posts: 51
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
The wheels I am looking at are +45mm offset and are 18 x 8 wide. I at least want 245/40/18s on them. I'd may go wider in back, but would also like to be able to rotate them, so I'm not sure which way I will go.

Giaco
Giacobazzi is offline  
Sponsored Links
Advertisement
 
Reply

  Pontiac GTO Forum > The 2004-2006 GTO > Wheels and tires

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Pontiac GTO Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Need winter 16"or 17" steel wheel suggestion first65now05 Wheels and tires 5 09-14-2011 10:06 PM
Need an 18" 05 wheel LS2Stampede Wheels and tires 1 07-02-2010 10:28 AM
Major sideways "kick" with burnouts/wheel spin?? 04black6mt 2004-2006 GTO General Discussion 6 08-14-2006 11:06 PM
Flat Tire "Org. Wheel Doesn't Fit in the Trunk" DJ_YellowGTO 2004-2006 GTO General Discussion 4 12-17-2004 04:03 PM

Posting Rules  
You may post new threads
You may 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
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome