It's absolutely true. I'll find the links later. At least two people have done completely independent testing.
And you could just apply common sense. A K&N has fewer pleats and therefore less surface area than a normal paper filter. So how do you think it restricts flow less? By having bigger pores. K&N themselves say that the filters are 98% effective. But guess what.. a quality paper filter is well over 99%. Sent from AutoGuide.com Free App
It is true that k&n air filters let more dirt through than most paper filters. The ONLY way to get more flow out of a direct fit filter is to lower its filtration efficiency. I challenge you (not you as in winkosmosis
) to get your oil analyzed after a full interval with the K&N filter. You WILL see higher amounts of silicons in your oil.
You have to really pay attention to the marketing. companies such as fram list their current efficiency numbers like "99% efficient at > 20 microns". that is not the same as or good as "99% efficient at 20 microns". K&N says their target is 98% efficiency... but at how many microns?
Food for thought