Hi. New post here. I may have missed another post that addresses this, so please be patient.

I have a 2009 528i XDRIVE. It has stock 17x7.5 wheels, 225 x 50x 17 with 20mm offset. My question is: If i move up to a wider tire and bigger diameter, do I need to increase the offset? IE. I go to an 18 x 8.5 wheel, should I move up to a 35mm offset. If shoeing my car with 19's should I increase or decrease the offset?

I have also seen a lot of posting about staggered sets versus "square" setups. When considering a staggered set-up, should I increase the offset on the back? As long as I am within 3% of original diameter, will I be within tolerance for traction control on my all wheel drive?

finally, I am considering a KW Variant 3 coilover suspension kit. How will this affect my choice of width (245?) when lowering? Does anyone know what the margin of error (+/-) for offset?

Thanks in advance for any assistance. I am considering MRR GT 8 (19 inch) or MRR GT 7's.

JW