Does anybody know the wheel dimensions and offset measurements for the stock wheels? I thought that was on here somewhere but I couldn’t dig it up.
Wheel Dimensions
- Thread starter Fubar
- Start date
ViperJoe
GT Owner
Optional BBS light weight forged wheels are:
Front:
5-lug, 4.5" bolt circle
6.90" backspacing
50 mm offset
18" dia x 9" wide
tire 235/45ZR-18
Rear:
5-lug, 4.5" bolt circle
7.295" backspacing
40 mm offset
19" dia x 11.5" wide
tire 315/40ZR19
Gentlemen,
Could somebody please give me a good understanding of exactly what "offset" and "backspacing" means as regards wheels?
Chip
Could somebody please give me a good understanding of exactly what "offset" and "backspacing" means as regards wheels?
Chip
Offset is a measurement in millimeters from the backside of the mounting plate to the center line of the wheel. A positive number puts the mounting plate further away from the backside of the rim. A negative measurement moves it closer to the backside. Since offset is based on the center line, the width does factor in. That is to say an 8-inch wide +45mm offset and 7-inch wide +45mm offset results in a 1/2" difference in wheel positioning. The 8-inch wide will be further into the wheel well. To gain a better understanding of the offset of a wheel, read our tech article on this topic.
Backspace measures the distance from the mounting plate to the back edge of the wheel. The higher the backspace the further into the fender well it will sit.
Offset:
http://blog.tirerack.com/blog/tire-rack-team-blog/what-is-rim-offset
Offset & backspacing:
http://blog.tirerack.com/blog/hunters-ramblings/what-is-wheel-offset-and-backspace
Last edited:
Funny, I just went to add it too that tire thread and it was already there. I guess that’s where I saw before.
Thanks again!
Thanks again!
2112
Blue/white 06'
Backspacing is so straightforward, I wish that were the predominant method of relating this issue.
