[NorthernSRX]

You should read this thread: Wheels for CT5V. Note offset and width specs in post #40.

My concern was fitment over the Brembo brakes (which the Sport model has). To the best of my knowledge, nobody has shared info that they've successfully fit 18s to a CT5 equipped with Brembos. That doesn't mean that nobody has succeeded, just that they haven't shared it here.

I had decided to run 19s in the winter and move to 20s for the summer - if my car ever gets built, that is...

 

[NorthernSRX]

But the technician in Canadian Tire told me do not use the non-manufacture size, otherwise will break the transmission at big chance.

Technician in Canadian Tire: wheels will break the transmission.

Me: WTF?

For those of you who don't live in Canada, Canadian Tire is where we should never go for mechanic advice.

So, if you stick with smaller wheels while maintaining the OEM diameter of the wheel/tire combo, there will be absolutely no harm to the vehicle. OTOH, going to Canadian Tire could absolutely harm the vehicle.

 

[NorthernSRX]

Lol @ the interactions with Canadian Tire. I can definitely see their staff saying things like that. Although it could be due to liability, not wanting to risk with non OE wheel sizes.

so back to my original question.. anyone running 18s winter wheel/tires on V/non-V with Brembos?

Not I. I have the stock 19s

 

[NorthernSRX]

Do you install the TPMS in your snow tires?

Every car I've ever owned that had TPMS sensors - and this goes back to 2004 - I have bought a set of sensors for my winter tires. This is a Cadillac. Why would I scrimp on $200 worth of sensors on a Cadillac?