Its well documented that K&N filters flow more by filtering less. Their sales and marketing departments will not address this question directly. Google is your friend. The folks that buy their marketing hype will fanatically defend them with no conclusive evidence that the filter works as well as stock. Use at your own risk!
A good aftermarket CAI will use a substantially larger filter with more surface area to increase flow. Drop in filters MUST filter less to flow more since they are the same size. The laws of physics apply.
2009 Murano LE AWD - Traded
2003 Excursion 4x4 7.3 PSD - DIESEL
1985 Mercedes 300SD - DIESEL
JGC LIMITED 4x4, CRD, MAXSTEEL-BLK/FROST INT, LG2, ORA2, BLK HTR, NAV., CD - DIESEL!
Harley FLSTFI '04