Depends on what your looking for.17's will look good and wont be a whole lot of rotating mass while 18's will look super badass but theres alot more rotating mass and will bring down your performance a little bit.Ive had both and the 17's looked awesome and were lightweight and I could tell cause I kept hitting the rev limiter in 1st,meaning it was reving up faster then I was used to lol.I have 16's right now BTW and they are not too small.