Yea K&n and others are completely out of their minds for doing anything to improve the factory setup right? I take it you dont have any experience first hand to experience a difference for yourself.
There are obviously other people who have actually used a less restrictive filter and had better results, why do people upgrade exhausts to a less restrictive setup if the R&D teams from factory have it perfect?
Read the reviews from people who have actually done it, based on your skepticism and close minded approach I would venture to say you've never done anything to make millions of dollars... and yes I have.
Bro, (Bro-ette? I don't wanna assume),
I've done it too. I also understand the things that I do need to be quantified with data, because my perception may not match reality. "Less restrictive" air filters and intakes ASSUME the solution to a "problem" is to free up airflow. It may or may not be. That's where the data comes in... I'll explain a bit more below. I like cars, bikes, atv's, etc, and I've spent a good amount of time learning about what make's em tick (or not tick if its a bad kind of tick....)
No Joke in high school I had a friend that disconnected the intake on his 93 Integra and put a pair of his moms pantyhose at the end of it and holy **** that thing was crazy fast and had a super loud intake growl after. It was at that point I realized that less restriction to the airflow the better the car could suck in air and perform better. Now i don't recommend pantyhose since that doesn't catch anything, But finding the balance between filtering enough and free flowing air is the key to having it perform better, not saying its the best for your engine but that's the cost of having some fun.
The louder you make something, the higher your perception of speed is. More than likely, with NO intake on and a set of pantyhose around the throttle body, that engine made LESS horsepower, not more. It was louder, probably sounded cool af, but I would wager MAJOR money on it not being faster than before.
I had an '86 bronco that I put a new motor in and added long tube headers. It sounded like a freaking NASCAR truck ripping up and down the road with no mufflers and just open headers on it. I LOVED that truck. I'd rip it up and down the road with it echoing off the mountains in our town, spitting during throttle overrun on downshifts, the whole nine. I still smile when I think about it. It was just a straight up HOOT. You know what made it even better to drive? A full exhaust that was balanced so it got back some low end torque and stopped sucking fuel even worse than a 351W Bronco is already known to do, lol. Yeah, it was quiet-er, but it was also more fun to be able to spin the rear tires WITH the exhaust on, instead of not being able to without.
More air in means more air needs to come out. Even when you allow more air out you need to balance the system. Can the valvetrain even let in the extra airflow you're providing? Can it push it out without becoming another bottleneck? Is the exhaust still scavenging properly with the "performance intake", 3" catback, or long tubes you slapped on? There are many things to consider.
The volume of each cylinder is fixed, it can only hold so much. And I highly doubt that the Engineers forgot to double check to make sure every intake stroke was filling each cylinder completely.
Also, "peak" power numbers mean nothing if your K&N (insert brand of choice) filter adds 10hp at 6000rpm but robs you of 25 hp and 30 lbs feet at 1500-2500 rpm where its most needed.
Buy whatever you want, and be happy with it, that's all cool. But the claims you're putting out just don't add up in the simple terms you're specifying for them. The thing I'm trying to avoid is the spread of misinformation about a product or mindset that will encourage others to waste money thinking they'll get results that just won't show up.