Originally Posted by ///M Rakete
This would be on BMW GTS wheels, 19x9 and 19x10. Stock non-ZCP suspension.
I'm pretty sure the answer is "No rubbing." based on reading and searches but I want to be sure before I drop money on the tires.
By going to a 255/35 tire, you are increasing the front tire diameter by 7mm compared to stock. By going to a 285/30 tire, you are decreasing the rear tire diameter by 14mm compared to stock. That is a 21mm F/R diameter differential change and will affect how your DSC functions to a small degree.
I am staying with the stock 245/35 front size and going to a 285/30 rear. This will give identical F/R tire diameters. I am running 12.5mm spacers on the front and this should offset any increase in understeer caused by increasing the rear tire width while keeping the front the same.
This is on ZCP wheels.