As far as I can see, the CT5's Brembo option is basically the same setup that was used on other Cadillac models - 345mm rotors with 4-piston Brembos - like the '14-19 CTS VSport or the CT6 (non V). Those models come from the factory with 18" wheels, so I don't see any reason to think that an appropriate 18" wheel (with proper spoke design to clear the Brembo calipers) won't fit on a CT5. Hell, I run 18" wheels on my CTS-V with 370mm rotors (a full inch larger) and 6-piston Brembos!
Seems silly to buy 19" wheels that you're not even sure will fit if 18"s is what you want.
Seems silly to buy 19" wheels that you're not even sure will fit if 18"s is what you want.
