I am using a K&N. I see no performance gains by using this filter. I mean, how much extra performance can you expect out of a I4 with 147hp? Maybe 2-3 bhp? Nothing that you would be able to feel. But I am using a K&N because I drive 25k miles per year, and it will be much cheaper for me in the long run to have a re-usable filter than to buy disposable air filters.

CAMRHEE Hybrid
Completed Mods: RK-Sport body kit, 18" LexusGS430 wheels 235/50ZR18 tires, TRD/SE springs, Rear Lip Spoiler, Terk XM-Direct, Smoked tail lights, Rear Bumper Applique, Front License Bracket, Lower Grill chrome inserts, K&N, Blaupunkt THB200A sub, moved rear HSD emblem
Future Mods: fog lights, black chrome my wheels