IS K&N AIR FILTER GOOD
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Joined: Mar 2009
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From: Nebraska
Originally Posted by borisnewn' post='946498' date='Jul 19 2009, 01:39 PM
k&n vs bmc reminds of me bbq sauce vs tomato ketchup on your steak
k&n and bmc are pretty close....its been said the bmc allows a little more air flow because it has less rubber area. I use a k&n because i found a good deal. either one is better than stock.
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Joined: May 2007
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From: Pittsburgh, PA
My Ride: 2008 Alpine White 550i Sport, Cream Beige Interior, 6-Sp Manual - retired 9/2011
Most of the M5 guys (M5Board) run BMC, and that's what I used in mine. They talk a lot of trash about K&N filters over there citing decreased performance vs. BMC, etc.
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From: So. Cal (SFV)
My Ride: 2011.5 Alpine White E90 M3 | Black Novillo Leather | Carbon Fiber Leather Trim | ZCP | ZP2 | M-DCT | Navigation | Moonroof | 6FL Mods: TMS 12.5mm spacers all around l Hawk HPS Brake Pads l OEM M3 Edition Grills l Paint Matched Side Gills l Key Hole D
K&N versus BMC filter would be a good dyno to see 
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Joined: Oct 2007
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From: Estonia
My Ride: 2005 545iA
I've heard some stories that air filters that use oil can kill the BMW MAF-s? Any truth to that? Any actual dyno pics of the filter used? I know that removing the filter on an 540i E39 gives around 10hp.