Yeah, this is good info and it points out how poorly the oiled foam type filters perform in actually filtering dirt. Not only that, but the "advantage" they have in flowing air is very limited for a short time, until they start to collect some particulate matter, at which point they perform substantially worse than a good paper filter. I have to say I'm surprised at how poorly the Amsoil filter performs, that's bad. I knew the F&N filters are crap, but I didn't know that Amsoil filters are so bad. Good info, thanks for posting. I'm filing a copy of that for future use.
I was very surprised myself when I saw the test results. GM does a good job obviously! This is the website where I found the article. https://www.nicoclub.com/archives/kn-vs-oem-filter.html
Good story, but keep in mind that a lot of the graphs do not start at zero, so can give misleading impressions. For instance at first glance the first graph might seem to indicate that the K&N filter has only a fourth of the efficiency as the AC filter, whereas it really is about 96% as efficient as the AC.
Not really, the K&N filter had an efficiency rating of 96.8%, the AC Delco had a rating of 99.93%. To put that in perspective, out of 10000 particles the AC filer removed 9993 of the particles, 7 particles passed throu; the K&N removed 9680, & 320 particles passed through. That's quite a difference between them.
Doesn't it say the AC Delco is the most restrictive to air flow, traps the most dirt, therefore being even more restrictive to air flow ??? My engines like to breathe man, they need air.
Most restrictive to start with, but as they start to collect particulate matter the AC continues to flow while the oiled foam types close up and become more restrictive. Look at the chart on page 9.
This is old...data, written in 2009. I know for fact that K&N changed their filter assembly. I'd bet that at least half of the filters in the above test have changed in some way. I've also seen, been part of chassis dyno tests of a three different filters a while back. About 2000. This dyno testing showed that the K&N filters outflowed both the OEM and the second high performance tested throughout the RPM (11,500 rpm) range . This was an airflow test only, not a test of their filtering abilities. I was NOT a fan of K&N at this time. Also, I know first hand, about K&N changing their filter construction... I bought a high power (185 h.p.), 2014 motorcycle (new) that came with a panel style K&N filter. I could see actual results first hand, as any time that I opened the airbox for any reason, I looked CLOSELY for dirt, grit of any kind, anyplace within the airbox. The first filter cleaning that I did, I actually wiped the interior with white cotton gloves (from work..!) to see EXACTLY how it was performing...I was VERY skeptical. I did this because, in the past, I would...NOT...use a K&N filter on anything but a full out race engine that got torn down every so often. The seal was dirt free also. The seal was a VERY tight assembly. It was a pain to get the seal and the inner and outer panels together because of the bead on the filter rings size. My white glove test...surprised the hell out of me. Not a discoloration or hint of dirt anywhere within the box, around the velocity stacks, nowhere did I find dirt. And I was actually 500 miles past the recommended cleaning period. I was amazed. So yea, things change. Mike
K&N air filters work great. I use them in everything. This is just more fake news from the big air filter fat cats.
You do realize that the kind of particulate matter that will cause the most damage is too small to see with the naked eye, right? People with good eyesight can only see down to about 30 - 40 microns. The particles that will do the most damage are smaller than that, what are known as "Clearance sized particles", because they are the right size to get between 2 moving parts and grind away. Silicon is the 2nd most common element on earth, and one of the hardest, it will cause a lot of damage very quickly. The air could be loaded with Silicon below 30 microns in size and you wouldn't see it at all with a white glove test.
If you love your engines, DO NOT use the oiled type air filters. Look at farm equipment and construction equipment, if those oiled gauze filters were so great, Cat, Cummins and John Deere would use them. Notice that OEM’s do not use them, they have to warranty engines. Sent from my iPhone using The H.A.M.B. mobile app
Blues - It's STILL...an old test. An...10+ year old test..! Companies change things. Some for the better, some not so much, some because of money..! Look at Fram filters. Once the top of the line oil and air filter. Last I saw, it's one to stay away from... Has been for some time. Just like oils, companise change their oil formulations every year or two. Why...mostly money..! Few get worse, some may even get better, that's a well known and proven fact. JUST...like oil and air filter companies. NO...filter is going to stop everything. That's absurd thinking to think one would..! The ONLY filter to stop ALL particle size, would be one than doesn't let enough air through that the engine can do anything but idle..! Come down to earth, and get real here. Beside, after a borescope check on the engine I note above, at about 56,000 or so miles, the cylinder walls...look just fine..! The air box shows NO...more oil blowby than it did the weekend after I drove it off the showroom floor. The oil is (visually) no more contaminated either. No...I never had the oil actually checked..! Just doesn't darken any faster than early on. Mike Ps - Truckdoctor - You apparently don't read well. The filter...the OEM...filter in the bike I describe above...has an oiled filter in it...FROM the factory..! I wouldn't surprised if their might not be others. Have you actually checked ALL OEM's ? Beside, when was the last time you drove your car more than about two feet in a corn field..? The streets may not be clean...but...
Well... Any filter is better than none, and for some reason I can't really understand it seems popular to run hotrods and customs with as small filters as possible, or open scoops/inlets that in the best cases has some wire mesh to keep birds out. The people who run these don't seem to like their engines, or don't understand what air filters do.
Unless you're racing baja class every weekend, you're gonna be just fine with a few extra "particulates".
That's a good point. And it seems funny to me that whenever the subject of engine overhaul comes up on this board the prevailing wisdom is that you have to do everything possible to ensure that the very best practices & tooling & parts are used. No skimping, no cutting corners, no cheeping out. That's how it's done. Such a contrast to the attitude shown in the post above, eh? A few extra particulates, it'll be alright...
Never had a problem in 25+ years, but go ahead and believe the charts someone could easily make in MS Powerpoint to say whatever they want.
Apparently I can read quite well, the OEM’s I was referring to were Auto Truck, and Equipment OEM’s. I don’t work on motorcycles for a living. Besides, I live 4 miles off the state highway on a gravel road. Ever driven down a gravel road on a dry day? I’ll trust my engines to the filters designed by the engine manufacturers. Sent from my iPhone using The H.A.M.B. mobile app
So what have you heard from oiled foam air filter companies have changed things to make them work better? The problem is with the technology itself, oiled foam. It is less effective as a media for filtering than paper media. I've been around cars for quite some time, not as long as a lot oguys around here, but since the 70's anyway, Fram has ALWAYS had a bad reputation since then. I don't know when they were considered the top, but not in my days. Actually, oil companies DO NOT change their formulations every year or two, that is false. The cost to have your formulated oil licensed by the API is extraordinary, >$1M each. Companies reformulate to meet new specifications that come around every few years, when the auto companies desire improvements in the oil to address new engine technologies. This is mostly driven by federal pollution legislation. And the results are increasing performance requirements, not reduced. The only issue with reduced performance comes from a forced reduction in ZDDP because of concerns with catalytic converter poisoning. In all other areas each new specification pushes the boundaries of oil performance, so oils are far more advanced then they were. Nobody reformulates their product to reduce the performance, you can't do that, because of the API licensing requirements. Your "well known and proven fact" is bullshit. I never implied any filter would, I just said oiled foam air cleaners do not perform as well as standard paper or cellulose media filters. They don't filter dirt as well, and they don't flow air as well once they start, you know, actually FILTERING the air, once they start accumulating particulate matter the flow performance drops off fast. So they are really only giving that benefit when clean, and overall they allow much more dirt into the engine.
I used K&Ms and had to replace MAF sensors every year until someone explained to me that the oil from them was coating the MAF sensors.
I used the oil mesh filters on motocross bikes and had to rering them every other race. When back to a paper filter, went all season on one set of rings. You could see the dirt in the carbs with oil mesh air cleaners. They are junk. I’ve been preaching that for years. Use what you want, I will never put one on anything I care about. Just me Bones
I'd say K&N is better than not running a filter though. I added them to my flathead to get away from the frog mouths. We'll see if they flow enough air to keep from choking the motor.
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