my rims are 17x7 and 17x8. right now i run 215 front and 245 rear. i know its possible to put 225 front and 255 rear on these rims, but would it have any negatives effects?

 

An 8" rim is not really wide enough to "comfortably" hold a 255 tire. You'd be pulling the bead in too tight and needing to reduce tire pressure just to get the contact patch to sit right. Reduced pressure will give a too soft a sidewall, hampering cornering performance. Typically, a 9" rim is better suited to a 255 tire.

 

umm guess ill stick with a 215 / 245 combo then...sucks tho.. i dont think they make falken RT615's in that size (215/45/17, 245/40/17) oh well, thanks!