At 31,696 miles I installed a K&N filter today. My turbo sound is markedly louder and I like it a LOT . I am not concerned with the possibility of dirt as I analyze every change and check the turbo for dirt/oil residue as well. As a side note, Blackstone has me at 8,000 mile intervals on Rotella T 15w40 dino. Silicon was at 6 last time. (23,529 miles). I will post the silicon at todays' change once I get it back.
Tony
Tony