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Old 05-01-2007, 08:09 AM   #3
MNBoxster
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Join Date: Sep 2005
Location: Minneapolis/St. Paul, Minnesota, USA
Posts: 3,308
Quote:
Originally Posted by djomlas
CJ,
you are sopposed to oil that filter

"The Importance of Oil
A K&N Air Filter is made of 4 to 6 layers of cotton gauze sandwiched between two epoxy-coated aluminum wire screens. The cotton is treated with a specially formulated grade of oil causing tackiness throughout the cotton’s microscopic strands. The nature of the cotton allows high volumes of airflow, and when combined with the tackiness of the oil creates a powerful filtering media that ensures engine protection. In contrast, most other media can not maintain the same balance of airflow and filtration throughout the filter's life without sacrificing one or the other"
Hi,

That's straight from the K&N Marketing Book! There is no special Oil, it's just straight 20W, used for years in Carburettor Damping Systems.

Cotton Gauze Filters are nothing new. They were developed for Racing where Airflow takes precedence over Protection. They don't filter as well, but consequently, they flow more air.

Ironically, a standard Paper Filter actually filters better the longer it's in service, but also becomes more restrictive.

With a K&N, small droplets of Oil will come off the cotton and settle on the Hot Film of the MAF causing it to send incorrect signals to the DME which in turn selects the wrong Maps for Fuel and Timing.

Also, in ISO 5011 tests against Paper Filters, the K&N clogged in 1/3 the time, meaning that at this point, it was actually more restrictive than, and consequently underperforming a standard Paper Filter. In proper Lab Testing, these Filters just don't live up to their claims.

K&N is all about Marketing. They first introduced it into the Racing World and quickly saturated that market. Then, they went to the Consumer, but not touting Performance merits, rather they marketed it for Longevity - the Million Mile Filter (so long as you clean and Oil it every 25k mi.). Once that segment was saturated, only then did K&N market it for increases in Performance on a Street Car. But, many of their claims are unsubstantiated, and they never mention any of the detriments to using one.

The choice is simple - slight performance gain vs. Engine Protection. The K&N lets in more air, but also more dirt. This has two problems: First is the dirt itself. About 1/3 of the particulates are very hard Silicates - think Sand (scoop up a handful of dirt from the shoulder on a Road or Expressway and carefully look at it - it's mostly Sand and this is what you're allowing into your Engine). These are very abrasive inside an Engine. The second is that only a portion of these are expelled through the Exhaust, the rest are trapped by the Motor Oil and reduce the Oil's Service Life, but also are continually circulated through the Engine, especially the Bearings. If choosing a K&N, the Oil Service Interval needs to be shortened significantly, and this all but negates any cost savings by reusing the Air Filter.

For me, the tradeoff of slightly more Performance isn't worth the risk of shortened Engine Life to use the K&N on a Street Car. I have used them on some of my Race Cars, but these usually have an Engine Rebuild annually, so it doesn't matter...

Happy Motoring!... Jim'99

Last edited by MNBoxster; 05-01-2007 at 11:45 AM.
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