Air Filter Testing..............by Bob the Oil Guy

[FieroBUZZ]

http://www.bobistheoilguy.com/airfilter/airtest1.htm

Interesting test.  It appears that there isn't a big difference if you are running a stock or near stock car.  That paper pop-in is just about as good as a foam filter that needs to be cleaned and oiled.

Aside from looking cool with a cone, a big airbox at the wheel well would probably serve just as well.  For the money involved you can change the filter more often.

[dguy]

http://www.bobistheoilguy.com/airfilter/airtest1.htm

Interesting test.  It appears that there isn't a big difference if you are running a stock or near stock car.  That paper pop-in is just about as good as a foam filter that needs to be cleaned and oiled.

I'd have to agree...  other than the theoretical cool factor  , of the four unmolested cars I've ever put K&Ns in the only tangible benefit has been longevity and perhaps one less item to pick up from a parts store at tune-up time.

On a carb'd motorcycle however... look out.  In most cases changing from paper to a drop-in foam or gauze filter will cause the engine to run moderately lean at an idle, and scary lean the moment you open the throttle enough to get off the pilot jets.  Not sure if FI bikes have similar breathing problems with the factory filters... no experience with 'em.