Originally Posted by David@Vengeance
Because GM put on 305/30/19 tires all around on the car.. which is quite odd..
That tire is a 26.2" tall setup, where the SS came factory with 28.6" tall tires, and the ZL1 with a 28.4"F/27.8"R tire.
Interesting - didn't know there was that big of a difference in tire height. Looks like people won't be able to run these wheels without getting a tune then. Ouch.