It's a little bigger than my old 9 inch K&N, it barely fits and rubs a little bit on the HID ballast but it's not a big deal. Here is a pic comparing to my old worn out 9x4 K&N. The car sounds louder with the Amsoil conical and there is more induction noise than with the closed mouth K&N. I went WOT around the block and the car chirped the tires really hard on the 1-2 shift so it's definately not down on power compared to the K&N. The Amsoil is made out of nanofiber and doesn't need to be oiled, it's cleaned by using a vacuum or blow dryer.