Finally had a chance to compare the oem wheel and tire setup with OZ and Cups,
OEM Front :
OEM Rear :
OZ Ultraleggera and Michelin Cups (265/35/18 Square Setup) :
So that's 1.2kg savings in the front and 3.1kg at the rears. Not bad considering 18 cups are really heavier then 19's. So far very happy with the results and the difference in handling is noticeable.
BTW, a bonus overall weight pic. Stock car, stock rims only mod is KW CS, 1453kg with full tank and tire mobility kit etc.
I know I need corner balancing. The car will go on a nice diet next week with AP's, Ti Exhaust, Rear seat delete, braille etc and then corner balance before Istanbul Park outing. I'll share each weight savings here.