Originally Posted by Nithmo

That doesn't really answer the question, though. I'm more concerned about having a 325, with that much extra meat, on a 10.5" wheel, in the back. It's different having the 325 on a 12" wide back wheel, as it isn't nearly as whatever the opposite of stretched is. (LoL)

I guess I should clarify- it's not the fitment that is a concern, but more so, what is the performance aspect? Is it safe to do high speed cornering with 40mm more tire placed on the same wheel?

I'm not surprised about the increased tread life and increased grip- those do definitely make sense. But what about acceleration, braking, and handling feel? I'd imagine if you went back down in size, the car would feel faster and nimbler. So much more rotational mass to spin (aka kills power being put down to the wheels, etc).

It's kind of like my daily beater... a 2006 Acura TL 6MT. I use the oem wheels for winter use, and have bigger wheels/tires for summer use. After I pull the summers off in the fall, the car feels completely different. You don't nearly notice it as much when you put the beefier tires on... but you totally feel it when you take them off and replace with something smaller.