I'm changing from the OEM Pirelli P Zero RFs on my CTS Vsport to non RF Michelin Pilot Super Sports. The Tire Rack agent called them the best summer tire ever manufactured. I'll have them installed soon. Picked up an inflator and Slim kit for the truck. No more RFs for me for a DD.newowner201 said:Have a 2015 ATS 2.0 with standard 17" wheels, apparently a lot of owners have changed out the run flats for much longer wearing better riding tires. Michelin makes a straight up replacement MXM4 225/45R17 with 55K warranty,from most posts the 30K run flats seem to be the high end for this type of tire with moderate driving. The car has a great handling feel to it and I guess some drivers get carried away. My question is are ther any issues with changing out the OEM tires for the same in non run flat and what be recommended for back up,one poster said ContinentialMobility Kit I do not believe the slime kits are recommended. My local Costco center states they have replaced a number of run flat equipped cars with standard tires. Any opinions ?