K&N Air Filter for 2009 Honda CR-V

[wemay]

Originally Posted By: skyship
BIGJL:
This forum does amaze with its hatred towards something that has been on sale in the UK for well over twenty years.
I always thought K&N was a UK company, perhaps that is significant.

It's not hatred, but just informed opinion based on reading factual test results and UOA Silicon contamination figures in particular.
Fitting a K & N filter only offers minimal performance improvement results, but often results in more long term engine wear.


For every negative UOA and 'independant' test against K&N, you can find positive ones. I can only site personal experience (UOA for my old 2005, 150k mile Mitsubishi Evolution VIII) where the Si was 6. Other friends using K&N on their Volvo 240 for 230k miles and still running strong. Neither engine ever cracked open. Does this all mean the K&N is filtering better than a paper type? Probably not. But it also alludes to the insignificant, miniscule increases (one grain of sand v two) of silicon that may be Introduced, depending on application, by using a K&N. If you are careful reoiling it as we are careful doing anything else with our engines, you will be fine, and you will be alleviating a tiny bit of stress on our landfills. That reason alone is enough for many users.

 

[wemay]

I also don't feel its worth the uproar either. Try it, run a UOA and decide for yourself. If you don't like it, switch back. No harm, no foul.

 

[wemay]

If I do switch back, it will be because I just don't like the cleaning and reoiling it. Good paper elements are much easier to buy new/dump old. Plus, you KNOW its clean.

 

[T_CUDA]

NEVER 1 time did a car come into my shop with a issue from a drop in K&N filter........ All the issues we see are people that OVER oil the filter. I have been using drop ins for over 10yrs and never one issue.

 

[Jim Allen]

Oiled cotton gauze (OCG) filters have a lower efficiency than many paper elements or synthetics. It's not always by a gigantic margin comparing an "average" paper filter to the OCG but some of the higher efficiency paper or synthetics can be markedly more efficient than OCG.

Whether that difference makes any difference to the life of your engine or even to a UOA will depend on the operating environment. Where the OCGs fail is in catching the fine dust. If your area is high in these fines, your engine will suffer more. If it is low in fines it will suffer less.

The main thing is to ask yourself.. what is the ADVANTAGE to an OCG filter?

It's not efficiency, unless you are comparing it to a [censored] filter because it's never better than average

It has better flow than most other types of filters. Is that an advantage? Maybe, but more so in a performance system than a drop in because the air filter housing is often as much of the restriction as is the filter element. This is highly variable according to the application. More airflow potential seldom offers a performance gain anyway unless other tuning changes are made to take advantage of it.

The ability to clean and reuse for years, if not decades? A decided plus if you intend on keeping the vehicle a long time. Still, that potential return on investment is mitigated by the fact that most people change their air filters way too often. Installing a restriction gauge and changing (or cleaning) the filter only when restriction indicates the right time can drastically increase the working life of a filter to two, three or four times (or more) what the OE lists as an interval.

Having used OCG filters for decades (And I still do in one application), I crunched the numbers for my situation and have now moved towards finding a high efficiency dry filter (one for which I can get specs and installing a restriction gauge.

 

[wemay]

All good points but i would like to add a couple more. A quality paper element, for my application at least, runs $22 (Napa Gold) vs K&N which was $43. In one filter change I recooped expenditures. In terms of efficiency, when compared to a Purolator Classic, the ISO 5011 efficiency ratings are 96.1%(clean) to 97.7%(dirty)K&N vs 96.5% for PC (as seen on their box). Now, i am sure that on a whole, Purolator filters are more efficient in a vast number of applications, but by how much, and where does the threshold lie that constitues any increased engine wear? There are just too many variables involved. The test of time has shown me that K&N is a quality product. Sorry, that was more than a 'couple.'

 

[Jim Allen]

Originally Posted By: wemay
All good points but i would like to add a couple more. A quality paper element, for my application at least, runs $22 (Napa Gold) vs K&N which was $43. In one filter change I recooped expenditures. In terms of efficiency, when compared to a Purolator Classic, the ISO 5011 efficiency ratings are 96.1%(clean) to 97.7%(dirty)K&N vs 96.5% for PC (as seen on their box). Now, i am sure that on a whole, Purolator filters are more efficient in a vast number of applications, but by how much, and where does the threshold lie that constitues any increased engine wear? There are just too many variables involved. The test of time has shown me that K&N is a quality product. Sorry, that was more than a 'couple.'

Before comparing efficiency ratings, you need to know whether it's an ISO 5011 on coarse dust or fine. I know that K&N advertises the coarse test. Here is an example of the difference:

Per Spicer Test: K&N #33-2155, ISO 5011: Coarse Dust= 96.8 %, Fine Dust 89.85% and those are final figures.

All filters show a difference between coarse and fine but more efficient filters narrow the gap.

Other Samples found quickly:

Per SWRI Tests: K&N #RE0870- ISO 5011 on Fine Dust- Initial= 93.23, Final= 96.13%

Per SWRI Tests AEM Dryflow 9-inch Uni- ISO 5011 on FIne Dust- 98.46 initial, 99.41 final

Anyway, if you want to argue for a product from the "how much junk can my engine ingest before it's harmed" standpoint, go right ahead. Especially in light of the fact that going a single percentage point, 98 percent efficiency filter to 99 percent, is a 50% decrease in the amount of contaminants ingested (that's a figure from a Parker engineer I interviewed).

As to engine wear, finding data in the light truck and car realm is indeed difficult. Many studies have been done on commercial/industrial equipment and the general consensus is that the cleaner the air, the cleaner the oil and the result is less wear. In some of the studies I have read, including some from GM and Cummins, it's stated that particles in the 1-10 micron range can be the most harmful to engines and are three times more likely to cause critical wear in piston rings and bearings than larger particles. The relative wear rates for 10-20 um particles, according to Cummins, is about 1.0 vs 3.5 dfor 5-10 um an and 0-5um at 3.3. One study that involved Montana mining equipment showed a 4x extension of engine life by keeping the oil at a cleaner level from ISO 22/17 vs 17/12 (oil whose primary contaminant was from the intake system).

In any case, you aren't wrong stating that within the realm of a street vehicle operated in a clean "normal" environment, the loss of engine life going from a 99% filter to a 97% filter might not be noticeable in the overall scheme of car ownership. The forever aspects of a cleanable filter are attractive but there are comparably price dry alternatives, such as the AEM Dryflow that are 99%+ on fines that offer the same sort of lifetime use. Best of both worlds IMO.

 

[wemay]

Again Jim, very good points. I am not sure if my figures stem from fine or coarse dust ISO 5011 testing as K&N sites both as being used, but i accept your premise. I have read the Cummings and GM reports as well as many others. The plethora of tests, reports, opinions are why i have always used my UOA as a guide. I am not a K&N lemming, i have even contemplated using a Napa Gold or Purolator recently and may still do so. But it isnt because i find K&N to be a poorly constructed or performing product. Its because i KNOW the Napa will filter better and the replacements are clean whereas no matter how well i clean a K&N, something could have been missed, and i am aproaching that cleaning stage. As for AFE, Cosworth, HKS, etc., If i ditch the K&N, it will be for the Napa, or equivalent (which i will run for 15k miles).

 

[wemay]

Ok Jim, your wisdom and opinion along wih lots of reading and research have swayed me. I have reversed my school of thought with regard to performance filters. Although the subject is highly polarizing, and many users (including myself in past applications) site many years of usage without any KNOWN engine wear, there is no disputing one simple fact. No K&N is as efficient a FILTER as a quality paper element like PureOne, Wix, Napa Gold etc. Now, how much wear from the extra Si (silicon or fine dust as seen in a used oil analysis) entering your engine is enough to cross the threshold of significant damage? Too many variables to be sure and quite possibly a lot more than the K&N allows in. But I now want an optimum filter to keep my engine as clean as possible without having that 'what if' thought as I drive past that very dusty road construction site on a daily basis. No tangible HP increase is worth my peace of mind anymore.

 

[mikefxu]

OEM and Air Filter Monitor for me: http://www.amazon.com/Wix-24801-Air-Filter-Monitor/dp/B0014BI1KA

 

[Jim Allen]

Very refreshing to see someone to change their mind in public. ( : < )

As I said before, the wear issue as it relates to light trucks and passenger cars is unknown. More data is available in the commercial realm and it points to having as efficient a filter as possible... but passenger vehicles live a pretty easy life in comparison. Would the difference between 97 and 99 percent make a huge difference in the operating life of a car driven in a mild city environment that will be kept for five years and traded in? Likely not. But then, why pay more for less?

I want to leave you, and everyone else, with this thought. This subject is only polarizing when people fixate on a brand or type and don't use logic or data. Though I am often seen arguing against OCG filters and am not a proponent of oiled cotton gauze filters from anyone (K&N isn't the only manufacturer of them), K&N is still a great company. They have a lot of expertise in the air filter world and have one of the best R&D labs in the aftermarket biz. OCG media aside, their filters are very high quality products. Since K&N and AEM are under the same roof, you are going to see some "cross pollination" and perhaps some exciting new developments.

Wemay: May I make one further recommendation... invest in a air filter restriction gauge. Filterminder or Donaldson Informer. Base your filter changes on that vs an arbitrary "15K". Do so, and you will be able to stretch your air filter life waaaaaay out no matter what type you buy. If you research that topic here, you will find people here who are running 50-60K or more on a "15K" air filter element.

 

[wemay]

Thank you Jim, sounds like a good investment. A sound argument makes for better judgement when decisions need to be made. Yours was sound.

Warren.

 

[ltslimjim]

X2, Jim Allen.

 

[Tuffy1760]

Awesome info... I was just gonna switch my car and truck but gonnas rethink it now... thanks