The Z51 is only 42 lbs heavier then the base coupe. I would have thought with the extra cooling, ELSD, bigger brakes, and some other goodies the Z51 would be about 100 lbs heavier. Good news. Changing the tires to non-run flats and deleting the muffler will make up for the 42 lbs. Hopefully we will start seeing some C8's come May or sooner.