A K&N HP series is good for 5k intervals, but I really have never considered them to be extended service filters. Myself and people I know with performance cars buy them for their higher flow rates and tougher construction, I.E. thicker can, thicker baseplate and silicone anti-drainback valve. A lot of the customers at our place with Lancer Evo's use them with thicker oil. These guys use Brad-Penn, Redline, etc. I use them from time to time on my street cars when I don't go OEM. I also don't go an inch over 5,000 miles on intervals. My good rides get Ford Racing filters.