From the '08 CTS manual: "If you have the spare tire on the vehicle, there may be a reduction in performance of the AWD system."

Why? The extra weight on the rear axel? If that's why, then it's practically anything you put in the trunk...

Or is this talking about if it's actually installed after you have a flat?

:hmm: :confused:

I think I just answered my own question since it says on not in the vehicle... DUH!

I think I just answered my own question since it says on not in the vehicle... DUH!

YES;)

Because when there's a randomly smaller, narrower temp tire and wheel thrown in the mix, that hurts overall balance and traction, especially in the case of the AWD system that can send power all around. Many systems, and I'm not sure of the CTS, actually will disable the AWD system when it senses a temp spare is on, to prevent any damage, etc. due to the imbalance.

But good answer to your own question, quickly, hah!

I know there's always a good reason why something is so. :yup:

Thanks! Good stuff. :)

YES;)

Because when there's a randomly smaller, narrower temp tire and wheel thrown in the mix, that hurts overall balance and traction, especially in the case of the AWD system that can send power all around. Many systems, and I'm not sure of the CTS, actually will disable the AWD system when it senses a temp spare is on, to prevent any damage, etc. due to the imbalance.

But good answer to your own question, quickly, hah!

hmmmmmmmmm, I am just curious....

how they know if we put a spare tire (maybe TPMS, then all custom rims without TPMS,,, not AWD... no... I hope my CTS is always in AWD mode...)?

hmmmmmmmmm, I am just curious....

how they know if we put a spare tire (maybe TPMS, then all custom rims without TPMS,,, not AWD... no... I hope my CTS is always in AWD mode...)?

each wheel has a speed sensor. one will be going faster than the other three (or slower if you put on a larger tire but that's not likely).
that's the old way they detected a tire with low pressure before TPMS.
note that it can also throw off the nav system accuracy.
rg