[cdmulders]

Interesting timing. I've just put on my oversized winter 245/50/18 tires onto my ACS-lowered 535xi. They rub the front fenders when I hit bumps. I'm not sure if this is caused by the oversized tire and lack of top clearance with the ACS springs or the aggressive offset making the oversized tire too flush with the fender (or maybe it's caused by both) but it raises a potential red flag to your question. My front wheels are 18" x 8" with effective ET of 26mm (ET 41 with 15mm spacer - it's a long story but last winter my winter wheels/tires without spacer started rubbing on the front suspension even before the car was lowered so I left on the spacer required for my summer front wheels when I switched to the winter wheels with an effective ET of 26).

Cheers.