Originally Posted by D_Frost

Looks clean! So shiny

Originally Posted by luv2sleep

I've spent some time doing the math on this "offset" issue so I'll throw in my .02.

The key point you are missing here is that the tightest gap between the control arm and the tire is where the tire curves (area between the sidewall and the tread). If you measure that angle, it's approximately 45 degrees; this 45 degrees is very important to know and I'll explain why later. With the stock set up (18x8 with 39mm offset rims), the "backspace" is 154mm-check out http://www.rimsntires.com/specs.jsp. Using a 20x9 with 40mm offset rims, the "backspace" is 168mm. This pushes the rim/tire 14mm into the wheel well. Okay, the 45 degree importance... Since the tighest area between the tire and the control arm is located on the curvature of the tire (the 45 degrees), we can solve this distance using simple geometry. Since the new rim/tire moves in an additonal 14mm horizontally, the gap between the tire and the control arm (the 45 degrees area) will decrease by only 7mm. Since the tighest distance between the tire and the control arm is about .75"/19.05mm (probably a little more), you will still have 12.05mm of space with the 20x9 40mmm offset.
I used the caveman method of measurement by sliding my index finger between the control arm and the tire, before and after the installation. You know what.... I was right! That 7mm is bearly noticeable. You can trust Harmann wheels when they say that they gurantee fitment. Enjoy!

Originally Posted by luv2sleep

I've spent some time doing the math on this "offset" issue so I'll throw in my .02.

The key point you are missing here is that the tightest gap between the control arm and the tire is where the tire curves (area between the sidewall and the tread). If you measure that angle, it's approximately 45 degrees; this 45 degrees is very important to know and I'll explain why later. With the stock set up (18x8 with 39mm offset rims), the "backspace" is 154mm-check out http://www.rimsntires.com/specs.jsp. Using a 20x9 with 40mm offset rims, the "backspace" is 168mm. This pushes the rim/tire 14mm into the wheel well. Okay, the 45 degree importance... Since the tighest area between the tire and the control arm is located on the curvature of the tire (the 45 degrees), we can solve this distance using simple geometry. Since the new rim/tire moves in an additonal 14mm horizontally, the gap between the tire and the control arm (the 45 degrees area) will decrease by only 7mm. Since the tighest distance between the tire and the control arm is about .75"/19.05mm (probably a little more), you will still have 12.05mm of space with the 20x9 40mmm offset.
I used the caveman method of measurement by sliding my index finger between the control arm and the tire, before and after the installation. You know what.... I was right! That 7mm is bearly noticeable. You can trust Harmann wheels when they say that they gurantee fitment. Enjoy!

Originally Posted by Yoshimura

You seems to omit that tire is also wider...

Originally Posted by luv2sleep

I did. I used an offset calculator ( http://www.rimsntires.com/specs.jsp) to figure all this out.

Originally Posted by Yoshimura

The backspace measurement you used don't take into account the tire width. Try a wider tire (for exemple a 375/30R20 that obviously won't fit) and see how the backspace measurement doesn't change...

The mesurement you are looking for (that take into account the tire dimension) is located in the Clearance section:

- Package is 11 mm closer to suspension component
- Package stick out 9 mm farther

The sum, 20 mm, is the difference between the 255 and 235 tires.