Any thoughts on the relative pros or cons of exchanging stock Honda air filter for a K&N? I heard somewhere that the oil used on the K&N can cause some problems. On the other hand I also hear of improvements in hp and mpg. Are there warranty issues? Thanks

 

If you are talking about the drop in filter, then do not expect gains.

The K&N filter is a re-useable and slightly less restrictive air filter -- difference is small to make any real hp gains. It's merely a replacement filter. The oil is used to trap dirt and a small amount of moisture.

There might be small gas mileage improvement, though don't count on it too much.

The real benefit of the filter is that you don't need to throw it away every 10K miles or whatever it is that you need to do so for the OEM filter.

 

Havn't swapped mine in the s2k yet, but I have ran K&N's in every car I've had in the past. Some cars do actually pick up some hp (and yes I mean the drop in kind) including a full 5whp on my otherwise stock 944 porsche (dyno'ed back to back, 2 runs each filter, of course the old one was a little rapdirty but could still see through it). I would expect with the stock cone type filter that the gains in the s2k would be much less maybe 1-2 hp but hard to tell since that is within dyno's error margin.

As K mentioned, the biggest benefit is not having to replace it, just clean and re-oil. Just make sure when oiling it that you don't over saturate it, the major downfall of reusable filters is if they are over oiled in certain cars they can cause problems. For example late 90's impreza Rs's were prone to maf sensor failure do to the extra oil building up on them, although their maf sensors were extremely unreliable as is.

 

pros: reusable/cleanable.

cons: will let in more particles

 

 

You're likely to see a higher level of silicon in an oil analysis, also. So punctual oil changes are imperative with a K&N air filter.

 

What you may have heard, was a result of idiot K&N owners who dipped their filters in the "tar sands" before installing. Over oiling is never a good thing.

 

I just put in a K&N drop in filter and yeah I felt changes but it was more due to the fact that the previous filter was pretty damn dirty. Sound is about the same although my roommates swear it sounds better <shrug> but overall I'm happy with it. Why did I get it? I promised myself a long time ago that if I got myself a great car such as the s2000 that I would always replace parts with equal or better and not buy anymore ebay filters (although I've used them with great results), and well, K&N sold me that they're better when really in truth a stock filter would do just about the same. Still, I sleep better at night.

 

Yes, ~$55 for a lifetime filter, plus oil to dress it every 10k mi vs $24 for a new filter every 10k mi. Its better money wise, and you're changing your oil regularly anyway so the extra dirt is not a problem.

 

There was a UOA posted here not that long ago from an engine using a K&N filter.
(haven't located it yet, maybe the poster remembers)
There were no higher then normal silicon levels.

About that K&N oil.
It has red colored die in it.
(to make it easy to see where you applied it)
That red color may fade over time.
That does NOT mean there isn't enough oil on your filter.
(I've made that mistake too)