I have a 03 Performance and I'm thinking about changing the tires soon. I have stock rims. My fronts are currently 225/4518R and rears are 245/45R18 as per stock settings.

I've found a good deal on a set of Potenza RE040 225/45R18 (set of four tires). My question is: would it matter much if I use the 225/45R18 tires on the rear tires as well (instead of 245/45R18)? Would that cause major disruption of the VDC?

 

I don’t think you should have a problem running that size (check the sticky at the top of the tire/wheel section in the forum and that can answer your question) but why would you want to do that? With 245 you will get better traction, less wheel spin, and just looks better on the car. I am not a big fan of potenza, I think you can get just as good of a performing tire if not better that last longer for a lot less money. I guess it all depends on how cheap is cheap, but I would not sacrifice the performance.