Use this calculator to determine size versus your stock tires
Custom rims, wheel tire packages for your ride - RIMSnTIRES.com
Probably the most important thing to watch is that there cannot be any significant difference between the front and rear tires or you will throw of the VDC. By that I mean you can be a couple of percentage off the stock size but the front and rears must be off by the same amount or the VDC will recognize it as the wheels are turning at different speeds and try and intervene.