i went to 205 in the front after getting a comfort level on here that it would be fine,and it has been.i did it to get bridgestone potenza re-11's,which at that time were available in the stock rear size of 245/40-17.now i believe that size is no longer available,so you have to go to 255's on re-11s,which means you are narrower than oem in front,and wider in the back,which i am less comfortable with.re-11a's are available in 245 for the rear,but not in any sizes that fit the front.
this is one reason i am trying 17/18 wheels.