Air Filter Basics
You basically have 3 filter medias;
1. paper, (treated & untreated)
2. foam, (single or multiple density)
3. fiber, (manmade chemical or natural)
The basic untreated paper element is the worst out of all the 3 medias. Our stock paper elements are basically just that. It is 'mildly' treated with just a light spraying ofoil and needs replacing most frequently.
The foam and treated fibers are the best for cleaning ability and longevity of filtration, in our RoadStars. The K&N's fall under the fiber class.
The multi density foam filters would be right up there with their abilities of filtering and longevity, 'but', they require a little more maintenance than the man-made fiber types. Plus, their longevity may or may not be as good as the man-made fiber filters. Mainly because of their natural ways of 'breaking-down', over time. They also don't absorb heat and flame very well under a backfiring thru the carb.
An air filter article is really, another of those topics that takes a LOT of info to write, and it WILL generate a lot of diverse opinions which is best,
World of difference in ALL the different medias and what the air filters are utilized for,
If I really had to write an indepth article of air filters and just our RoadStars , , I'd have to take at least a year off the Forum just for all the research and testing that needs to be done, LOL ! ! !
I wasn't fussing at you about the air filter article that you posted. Really. Just wanted to make a comment that folks take an article like that with a grain of salt and just remember, we ride a low compression, low RPM, V-twin.
We've all seen the articles about Brand 'X' oil and how it's THE BEST, 'because', it was utilized in a fleet of 4 million 18 wheelers, that made non-stop convoy trips to Pluto and back, with only 1 oil change, etc., etc., etc.,
Well, that's all well and good for the 18-wheelers, but folks want to say that Brand 'X' oil should be used in our RoadStars because of that 'fleet test' with a HIGH compression diesel motors, LOL ! ! ! WRONG,
Love reading the different articles of different products, when the test vehicle is a stock 2 cylinder V-twin, regardless if they're water cooled, air cooled, etc. At least the article is talking about a V-twin, LOL ! !
Joel (Odo)