Since I didn't find the "backspace" for out 17" stock wheels posted anywhere, I searched for "offset" and found the following. I don't know if this is for the Sedan or the Coupe.

Diameter Width: 17"x7"
Bolt Pattern: 5x114.3mm
Offset: 45mm(?)

Is "offset" the distance, in millimeters, from the "outboard edge" of the wheel rim to the crown of the hub or the face of the disk rotor?

Is "backspace" the distance, in inches, from the "inboard edge" of the wheel rim to the face of the disk rotor?

Screamin' Daemon - L5AT <P ID="edit"><FONT class="small"><EM>Edited by suprhulk on 02/18/03 06:39 AM.</EM></FONT></P>

 

I think offset is the distance from the centerline of the rim. If I'm right, then a 7" rim (177.8mm) with a 45mm offset would be 43.9mm in from the outside edge of the rim (177.8 / 2 - 45). I'm going off memory from what I've read. I've not heard the term "backspace" before.


2003.5 G35 Sedan Desert Platinum/Graphite Premium/Sport/Aero/Nav/Winter

 

Suprhulk, I've read those fugures b4 but can't put my finger on them right now. From memory the offset for the Sedan's wheels is 45mm and for the Coupe's wheels it's 25mm. I'm fairly sure, but not 100%.
Never heard of backspace, sorry...........[img]/w3timages/icons/smile.gif[/img]

<font color=red>Gsedanman</font color=red>

 

I've found the specs on offsets for both the Coupe and Sedan:
Sedan: 16"- offset=40mm
............17"-offset=45mm

Coupe: Front-17"=30mm
..................18"=30mm
.........Rear- 17"=33mm
...................18"=30mm

Got the info from the G35 Sport Coupe O/M (Dec-02 edition)
Section 10, p8.
[img]/w3timages/icons/smile.gif[/img]

<font color=red>Gsedanman</font color=red>

 

FYI.

Here a URL which best explains both "offset" and "backspace". (The Infiniti dealer printed of an even more informative page but I didn't catch what web site he was using.)

USAComp's "Offset" page

Synopsis:
Both "offset" and "backspace" are measurements which start from the hub mounting surface of the wheel. The difference is where the measurement ends.

Offset: Distance from hub mounting surface to the "centerline" of the wheel. Here "centerline" is the wheel width divided by two. I.E. From the hub mounting surface to a plane running through the middle of the wheel parallel to the wheel rim. This is important when determining if the wheel and/or tire is going to hit any "street side" part of the wheel well. (Don't forget wheel well flare and compression of suspension.) The larger the offset the more the wheel is set back into the wheel well.

Backspace: Distance from hub mounting surface to the edge of the inside (versus "street side") rim of the wheel. This is important when determining if the wheel and/or tire is going to hit any part on the inside of the wheel well. E.G. Suspension, struts, coils, links, frame, etc... Here again, the larger the backspace the farther the inside rim is from the "street side" of the wheel well.

Other things which affect the determination of whether or not a wheel will fit is wheel diameter and "bolt pattern", tire "section" width and tire profile.

Aaaaggghhh! My head hurts.

While web sites like "Tire Rack" and "Discount Tire" make it easy to find wheels which will fit your car, if they don't have a wheel that you like, you have to do your own research.

Screamin' Daemon - L5AT

 

Excellent reference material. Thanks for posting.[img]/w3timages/icons/smile.gif[/img]

<font color=red>Gsedanman</font color=red>

 

Thanks.

But I still went down to my local "Discount Tires" retail store in order to talk to my favorite wheel/tire guy about whether or not the Infiniti M45 18x7.5 5x114.3 40mm wheels I've ordered will work on my G35 Sport Coupe. I was especially worried about changing from the 17x8 33mm back wheels.

He laughed and said "You won't be able to tell any difference."

Actually, I looked up the wheel specs in an '03 M45 manual and the manual stated a 35mm offset. Even better considering I'm going down from a 8" width to a 7.5" width.

Screamin' Daemon - L5AT