BBS CH -what is effect of offset change and going wider?

[A4B07]

Hi All,

I am planning on getting new BBS CH's 18 x 8.5-The size available now.

The problem is the OEM BBS CH's on A4’s were 18x8 with an offset of 43. The BBS CH's available now are 18x8.5 offset of 35mm.

The 35 offset puts the inside of the rim at same place as OEM, the outside of the rim at 1.5cm pushed out, and center line of wheel at about 7.5mm out.
This pushes the scrub angle out a bit and therefore should change the steering behavior slightly.

Question I have is for those of you who may have doen something similar—Going to a smaller offset or wider wheels—anything that moves the center line out and changes scrub angle/radius (or kingpin angle).

A) Is the 7.5-8mm significant or at all noticeable?
B) If there is a change, what is the effect on :

1) steering effort
2) Stability in straight line (slightly wider track)
3) Return to center force & Bump steer behavior
4) Other handling issues considering this is a Quattro system

Or is this just too small of a change?

Already talked to Tirerack about this but wanted to see if anyone has direct experience with changing offsets like this.

Thanks.

[Doc@tirerack]

When I made a similar change in offset (not width), there was a little less steering effort and better cornering, but I felt a little less stability at first, perhaps due to the extra steering response seemed to magnify any small steering input. That's my 2cents anyway !

[fritzner]

how does width and offset relate??..

if you have 8" and a 8.5" wheel, both with a 35mm offset..

are the centerlines the same, the position of the front surface the same, or the position of the rear surface the same??..

thanks..

[Doc@tirerack]

ET is measured from the centerline of the wheel (so width is not a factor in the actual measurement). However, as the wheel gets wider, the ET may have to be adjusted to gain additional clearance (relative to the strut or fenderlip)

[onemoremile]

Google "wheel offset calculator" and you'll find a few links that make understanding it easy.