However, standard rim size was 7.5 front and 8.5 rear. Some guys go wider at the rear, but BMW chose 235 tyres all round when this car left the factory ...
Later it was updated to 225 on the front and 245 on the rear, because the american's all killed themselves as the car didnt really understeer and just went into snap oversteer.
I run 235 front and 245 rear, probably going to 255 rear next.