if you go 17's then you need to have your arches rolled
also, acceleration will be slower also, due to the extra weight & turnin force required to turn a 17 rather than a 15
also, 17's might give extra grip in the dry but in the wet it is the reverse it gives less grip than a 15
15's are what u want, anything else just doesnt look right. even the 16's i had on just didnt look right!!