JerryJeff

That's why I bought my AEV Snorkel

turtoni

No that looks wrong way up to me. The *lip* should be on the top..... Why would the lip be on the bottom? Does make any design sense to have the lip on the bottom....

turtoni

I agree. The thicker side should be down in my opinion.

Crasher

The pleats shoud be facing the incoming air on any pleated filter. We used to run the K&N filters until we lost a Ford 7.3 diesel engine to dirt contamination through the intake. Yes, we cleaned and lubricated it properly every 5000 miles. The engine was burning a qt of oil in 400 miles after 35,000 miles with a K&N. We went back to paper on our fleet and no more problems. They allow more air, but also allow more dirt. There is no substitute for a good quality paper filter. Regardless, what you use, the pleats face the incoming air.

turtoni

"The air filter industry uses the ISO 5011 testing protocol when testing filtration efficiency and dust capacity. The test protocol calls for the introduction of a measured amount of “test dust” into the air filter at a selected airflow rate. The test is then terminated after the filter reaches a selected level of restriction (terminal test pressure). The test protocol then measures the percentage of dust retained by the filter (efficiency) and the total amount of dust held by the filter (capacity).



The ISO 5011 protocol allows for flexibility in test design and choice in the variables selected for the test. This means that you can change the grade of test dust, the airflow rate, the beginning and end points of the test, and other factors while still being in conformity with the protocol. For example, the filter can be tested in a special “test housing” or in the factory air box. As you can see, the ISO 5011 test protocol it is not an absolute test or standard; it is meant to help engineers design air filters by holding conditions constant while one variable is changed to measure the change impact.

If all the variables are consistent between two tests, the results can be used to compare the filtration capabilities of two air filters in a laboratory setting under specific controlled conditions. However, any filtration measurement will only be meaningful if it includes disclosure of the test variables that were selected, such as grade of test dust, airflow rate and terminal test pressure.

Because the ISO 5011 protocol uses fixed airflow and is often conducted with the air filter in “test housing,” it is not intended to develop a filtration number you will experience in actual use. While in a vehicle, an air filter will experience a range of operating conditions, airflow and dust feed rates, etc.

Under the parameters of the ISO test, the user may select the grade of test dust used. The content of the two most commonly used types of ISO test dust for air filters are as follows:

ISO COARSE TEST DUST ISO FINE TEST DUST
Particle Size in Micrometers (Microns) Percent by Volume
(+/- 3%)
Particle Size in Micrometers (Microns)
Percent by Volume
(+/- 3%)

001 – 005
10.5%
01 – 05
36.0%

005 – 010
11.5%
05 – 10
18.0%

010 – 020
14.0%
10 – 20
20.0%

020 – 040
25.0%
20 – 40
17.0%

040 – 120
37.0%
40 – 120
09.0%

120 – 180
02.0%





As has become customary in the automotive industry, we use Coarse Test Dust for gasoline engine air filters and Fine Test Dust for diesel engine air filters. This practice of using different grades of test dust developed because Diesel engines require higher levels of filtration because they operate at much higher compression and require finer tolerances than Gasoline engines.

K&N operates an in-house filtration test lab with two different testing machines built in consultation with Southwest Research Institute, one of the pre-eminent testing companies in the world. Most of the filtration testing we perform on our air filters is performed in our lab that operates on a year round basis. Occasionally, we send air filters out for testing with an independent lab, either to confirm our in-house testing or to reduce the capacity requirements on our lab. We perform tests of filters both in the factory air box and in SAE/ISO recommended test housing fixtures. Our goal is to design filters with the maximum possible airflow achievable while providing guaranteed engine protection.

Our actual air filters when tested generally demonstrate a cumulative filtration efficiency of between 96% and 99%. All this testing we do allows us to guarantee our air filters provide all the protection your vehicle will ever need."

h ttp://www.knfilters.com/efficiency_testing.htm

tslewisz

Over the years I've run K&N filters in many vehicles. When I got my '05 Dodge diesel and began to do some reading, K&N was pretty universally advised against on the forums I found; multiple instances of dirt getting past them. Paper filters are the way to go on diesels, apparently. Some are getting good results w/ the new-ish Amsoil nanofiber filters, too.

I think turbo diesels just suck SO much air that they just aren't suitable for some reason.

The BMW GS motorcycle (I bought one of those a couple years ago) community pretty much espises them as well.

I've decided not to trust my offroad vehicles' engines to K&N filters. I have no reservations about using them on road. It's paper or oiled foam for me for anything that'll see off road duty.

Crasher

Somewhere I saw a test comparison run by a construction company lab to determine which type of filter would do the best job of filtering the air going into their expensive offroad heavy equipment. It was extensive and included several brands of paper and oiled reusable filters. The result of the testing showed them that a good quality paper filter provided the most filtration.

If the K&N or any other reusable filter was truely a better filter that offered better performance and improved mpg, they would be standard equipment on new cars and trucks. That would be the cheapest improvement they could buy.

To me, the afore mentioned test, my own experience and what the auto industry uses, speaks volumes to me regarding what filter I will use in all of my engines. Oh, and I will install it with the pleats toward the incoming air.

Tuto

Ok finally - With way does the filter goes in the air box. ?

The thick part up towards the cover or down into the body of the air box. ?

The filter has no arrows indicating the air flow. Someone tell the manufacturer please !

hx15537

I've had my K&N for about 25K miles. I got a 1-2 mpg increase on the highway, and no noticeable increase around town.

I've never had any problems with it. I know it's time to clean it when my highway mileage starts to decrease though.

hx15537

I installed it so that it sits in flush on the top of the box. The protruding section pointed down into the box.