Oh BS. K&Ns are used by desert racing cars and bikes. K&Ns have been used in all forms of off-road racing for decades. I race, I know what to trust and what to avoid and I don't relay on some half-witted web site's "test"

If they are so great, why don't the OEM motorcycle manufacturers use them?  The patents ran out years ago, so anyone can produce "surgical guaze" filters.   Oiled guaze filters are freer flowing because they pass more dirt - FACT.  Paper filter are more restrictive because they block more dirt - FACT. 

You know, you guys (both sides of the aisle) aren't going to convince either side to switch so you might as well give up.  All you're going to do is get your knickers in a twist and I'll have to lock the thread eventually.  Who cares who uses what type of filter.  It's like oil, oil filters, and car tires....  We got our preferences just like anyone else.

Could I suggest going to the K&N website? 

I have no dog in this K&N debate, but I got a chuckle out of the above. Sure K&N's site is going to tell you they are the best money can buy. Know what? Fram's web page will tell you the same thing about Fram products. Does that make it true?

Oh BS. K&Ns are used by desert racing cars and bikes. K&Ns have been used in all forms of off-road racing for decades.

Race teams are a poor example.... they are in it to win a race and care nothing about engine cleanliness because they are going to tear it down and rebuild the next day.

Filter?  I thought those were for weaklings!  I removed mine when I got the bike.

Obviously just foolin' about.  I use the OEM and change them out more often than recommended because I live in Kansas, land of the debris filled wind.  Now that I think about it I don't change it out enough since the book calls for a filter change anytime the bike rode through rain.

[anectodal evidence]
I dunnow. Been running a K&N on my C-10 for 160k miles. Dirt roads in CO, during pollen season, locust swarms, ... Every couple of years I bang/scrape/brush the caked on dust and bugs off the filter, rotate it L to R and put it back in. I think I've actually cleaned and re-oiled it twice.
[/anecdotal evidence]

Is it worth the cost? You betcha, the filter lasts forever. A clean and re-oil @ 10k, 20k, whatever miles will set you back a couple of pennies (in 1994 dollars). And you get two uber snarky K&N decals in the package too! 

Rick

Here is where Rick is right on the target; as a K&N Air Filter gets dirty it gets to filtering better as the larger pores in the media are closed in by captured particulate yet it will still flow an adequate amount of air due to its design. The key to getting the best filtering performance out of a K&N is to NOT clean it unless it has become clogged and restrictive.

Race teams are a poor example.... they are in it to win a race and care nothing about engine cleanliness because they are going to tear it down and rebuild the next day.

Uhhh . . . NO. As a racer, which I am and have been for decades, Rule #1 is You Have To Finish To Win. Immense expense and effort in all types of racing, pro to amateur, is spent in meeting that rule. Doesn't matter how fast you are at the beginning if you're not around at the end.

I very much care how long my engine lasts and I expect it to last for many races with as little expenditure on my end as I can manage.

Even Top Fuel drag racers who literally rebuild their engines after each run, still build things so it will last as long as needed.

I don't work for K&N or own their stock. I do use their products, so when someone with an opinion but no actual experience with the product quotes some web site as "proof" of something, well that's annoying.

I have used K&N's for years in different vehicles with mixed results.   My Superhawk seems to run better with it but my Passat and Altima both struggled with it.   My mechanic said the oil on the filter can clog the system on some vehicles.   I used an aftermarket air filter in my 800 Polaris Sportsman EFI and it made it backfire.  Switched back to the OEM and it runs fine.   Just my experience.

I race, I know what to trust and what to avoid and I don't relay on some half-witted web site's "test"

Uhhh . . . NO. As a racer, which I am and have been for decades,

Ummm, you said that already ..... but it doesnt change anything.  Does K&N make a good product, sure they do. Is it the best of the best and there is nothing better? Probably not, but that is up to each owner to decide what is best for his/her bike, riding conditions, and maintainance practices. The OEM filter is a good quality product and some people may like throwing in a fresh filter and not having to clean the old one.

You know, you guys (both sides of the aisle) aren't going to convince either side to switch so you might as well give up.  All you're going to do is get your knickers in a twist and I'll have to lock the thread eventually.  Who cares who uses what type of filter.  It's like oil, oil filters, and car tires....  We got our preferences just like anyone else.

The facts:
1)OEM filters out 5x more dirt than K&N. Different research studies by independent sources (including one public university) confirm this.
 2)No vehicle comes from the factory with a cotton filter. FWIW, my mom's old Lincoln came with a sticker on the air cleaner saying something along the lines of "Do not use cotton gauze filters". I assumed that it was due to how K&N filters can destroy MAF's.
3) There is no evidence that a C14 (or most any other vehicle) will make more hp with a K&N filter instead of a paper filter. If cotton filters really could make more power, I am sure at least one of the car or motorcycle companies would have jumped on it and put it in one of their top line models by now.
Proponents of K&N filters will say that they save $ on filters with K&N as they are reusable. That can be true, but don't forget to factor in the cost of their recharge kits. Everything else claimed for it is purely anecdotal, non factual stuff like "I drove 150K miles with one!" or "I know a race team that use it!".
Based on the facts, using a K&N filter to save $ makes as much sense as changing the oil at double the miles kawa says to (to save a little $).
Here's a paste of another independent study:

The following data is provided by Testand Corp. in Rhode Island. Testand makes the $285,000 machines that perform the SAE J726/ISO 5011 air filter test standard. Any air filter that wants to be tested for performance and efficiency uses this test. These tests cost $1,700 per filter when done by an independent laboratory. Testand Corp. was interested in the comparison study and agreed to do the study for us.

Every filter listed was tested in an identical manner according to the SAE/ISO test standard> Here are the results:


In the order of EFFICIENCY (ability to filter dirt) the results are as follows:

FILTER % EFFICIENCY

AC Delco OE 99.93%
Baldwin paper 99.72%
No name pargain paper 99.32%
AFE Pro Guard 7 panel filter 99.23%
WIX/Napa Gold 99.03%
Purolator paper 98.73%
Amsoil, new style 98.63%
UNI 97.93%
K&N 96.80%


FLOW RESTRICTION from best to worst. Remember, 27.7 inches of water = 1 psi. So, 1 inch of water = .036 psi. The worst (AC Delco) at 6.23 in. water and the best (K&N) at 4.54 in. water is a difference of 1.69 in. of water or a "whopping" .0608 psi. Virtually negligible.

In order from least restricive to most:

FILTER RESTRICTION in inches of water

K&N 4.54
Mystery bargain 4.78
AFE Pro Guard 4.99
Purolator 5.05
WIX/Napa Gold 5.06
UNI 5.40
Baldwin 5.71
Amsoil 5.88
AC Delco 6.23


DIRT HOLDING CAPACITY. From best to worst. This is the AMOUNT of test dirt it took to create an ADDITIONAL 10 inches of restriction. At that point the test is terminated. This is an indication of HOW LONG a filter is good before it must be cleaned or replaced.

FILTER Dirt Holding Capacity

AC Delco 573.898 grams
WIX/Napa Gold 447.366 g
Purolator 388.659 g
Baldwin 388.154 g
UNI 374.638 g
Mystery bargain 350.402 g
AFE Pro Guard 7 232.516 g
K&N 211.580 g
Amsoil 196.323 g


TOTAL DIRT PASSING THE FILTER DURING THE TEST. This is how much dirt your engine will take in if you use the filter for the duration that would cause the filter to become "dirty" enough to need replacement or cleaning. The "Dirt Passing The Filter" is the dirt collected by the "POST FILTER" during the SAE/ISO test.

In order from best to worst, the filters performed as follows:

FILTER DIRT IN GRAMS PASSED

AC Delco 0.4g
Baldwin 1.1g
AFE Pro Guard 7 1.8g
Mystery bargain 2.4g
Amsoil 2.7g
WIX/Napa Gold 4.4g
Purolator 5.0g
K&N 6.0g
UNI 7.9g

NOTE: During the test the Purolator was reported to have had a seal failure which gave it higher than expected dirt passing.

My mechanic said the oil on the filter can clog the system on some vehicles.

Agreed. It's a known problem on some Toyota models. The oil contaminates the MAF (Mass Airflow Wire) wire.

Agreed. It's a known problem on some Toyota models. The oil contaminates the MAF (Mass Airflow Wire) wire.

    Not on my Prius.  It's got 212k on it and most of those with a K&N.