K&N filters

I use to repair and service ATVs, Polaris was my specialty. Almost all K&Ns I ran into had dust in the intake. I got to I wouldn’t service the darn filter because I didn’t want to be blamed for engine failures. Every one I told changed them back to the stock filter.

Maybe they would get more than 10k with a paper filter.
Planned obsolescence?

I took a sales man advice and switched from the paper OEM to a foam uni filter on my Polaris RZR. I dusted the engine in just one ride. After researching the subject I found that many others had the same experience.

I ran K&N on my Dodge Cummins and found dust in the intake.

Just say no to the K&N koolaid.

ktmrfs wrote:
What works in one case may not be very practical in another case. And these engines are often lucky to get 10K miles on them in their lifetime, not 100-300K miles.

Agree to most everything. The oil is very sticky and very much unlike K&N oil but is purpose designed for a different environment.

I was only responding to the very broad comment, from another poster, that oiled foam filters are complete junk and a waste of money. That may be true in some cases but is not 100% true, also per my taking things a bit out of context in this thread.

The part I don't completely agree with is the "lucky to get 10k miles" part. That may be true for Polaris products, some of which go up in flames well before 10k miles, but I have plenty of friends who regularly use their "other" machines and are pushing 20k-30k miles on them. Certainly that is a far cry from on-road vehicles with reasonable expectations of up to 300k but those vehicles do not see the same sort of abuse either. Comes back to what they were designed for. :)

time2roll wrote:

RedRocket204 wrote:

Lynnmor wrote:
I consider the use of oiled foam filters a total waste of money and a harmful product.

In no way what I am about to say is condoning the use of K&N filters as I do not use them. I've read the independent tests and will not use K&N on any of my vehicles.

Now, I may be taking your comment out of an assumed context, but you do know that OHV ATVs, Side-by-Sides and dirtbikes use oiled foam air filters and those vehicles are run in FAR WORSE dusty conditions than on-road vehicles. Heck, I just returned from a 6 day ATV riding trip in central CO and here is the result of 6 days of riding on an air filter. Picture is a comparison of my second cleaned and freshly identical air filter. This was from about 500 miles of trail riding. And yes, the oiled foam air filters do an excellent job filtering the air.

They all catch something. How much passes is the issue. Any excess oil can really mess up the sensors or valve body.

yes, OHV's very often have oiled filters and they work (at least for me) very well in the conditions they are designed for. But in context, Mine are good for anywhere from 200-500 miles of dusty conditions before they are plugged bad enough to cause the bike to run rich. The foam is quite thick, and the "oil" is definitely different than K&N oil. very very very sticky stuff. They do an excellent job of filtering in this case, but the OHV was designed for that type of filter use from the start and expected to be changed very often under most conditions. What works in one case may not be very practical in another case. And these engines are often lucky to get 10K miles on them in their lifetime, not 100-300K miles.

time2roll wrote:
They all catch something. How much passes is the issue. Any excess oil can really mess up the sensors or valve body.

Which was the point that OHV oiled foam air filters are catching the dust. I do not have any dust accumulating in the throttle body. If you are commenting becuse you don't believe oiled foam air filters catch enough of the dust, why would OHVs come with OEM oiled foam filters when they are commonly in EXTREME dusty conditions? Seems like it would be a nightmare for warranty work to be constantly replacing rings from inferior air filters :R

There are quality oiled foam filters made. I do not believe K&N is one of them though. Although I do not believe K&N air filters are actually considered foam, more of a textile.

Terryallan wrote:
Thing is. for just any high flow filter. The engine computer compensates for it. so no real gain.

Gas yes, diesel no.

Thing is. for just any high flow filter. The engine computer compensates for it. so no real gain.

As for the cold intake. Unless you also open the exhaust. all that air coming in has no where to go. so once again. Little to no gain. To really make a difference you have to open both the intake, and the exhaust, and tune accordingly.

RedRocket204 wrote:

Lynnmor wrote:
I consider the use of oiled foam filters a total waste of money and a harmful product.

In no way what I am about to say is condoning the use of K&N filters as I do not use them. I've read the independent tests and will not use K&N on any of my vehicles.

Now, I may be taking your comment out of an assumed context, but you do know that OHV ATVs, Side-by-Sides and dirtbikes use oiled foam air filters and those vehicles are run in FAR WORSE dusty conditions than on-road vehicles. Heck, I just returned from a 6 day ATV riding trip in central CO and here is the result of 6 days of riding on an air filter. Picture is a comparison of my second cleaned and freshly identical air filter. This was from about 500 miles of trail riding. And yes, the oiled foam air filters do an excellent job filtering the air.

They all catch something. How much passes is the issue. Any excess oil can really mess up the sensors or valve body.

Here is one test of air filters: Test


I especially liked this comment: "In 60 minutes the AC Filter accumulated 574gms of dirt and passed only 0.4gms. After only 24 minutes the K&N had accumulated 221gms of dirt but passed 7.0gms."