if ur doing all 4, u can get away with it...its just a lower profile tire. so ull have more gap. why do u want to do it? im not sure how it would affect ur abs or traction control, if you have it...on awd cars, changing the size can affect those systems. usually, tho, u want to keep the aspect ratio the same, by changing both the width and height...like a 205/50/16 to a 215/40/16, and so on.