K&N Air Filters (car engine, vehicles, best, tuning)

[skins_fan82]

i put a K&A conical air filter on my modified crown vic years ago, I noticed a pretty big difference after I got my performance chip reflashed. had to clean the MAF every 3 months or so though, as lubricant stuff from the filter would get in there.

[ramkobe]

Ever heard of the Placebo Effect?

[ramkobe]

K&N is pretty bad according to this article.

K&N Air Filter Review - Debunking the Myths (and why OEM is better)

[Billy_J]

Originally Posted by KurtAZ

...I bought a K&N replacement air filter for my 2012 Fusion I-4 that normally gets 29.2 MPG per the dashboard read. I reset the MPG this morning before I left the house...clocked in at 35.5 MPG for my normal commute this morning. Pretty stinkin' sweet for a $38 part I think.

If that is true, then why don't automobile manufacturers (which have WHOLE FLOORS of engineers) install similar filters?

I should think their sales would jump through the roof if this was possible? And they would do so with the quickness if it was possible?

In the past I have read of people who have replaced their factory air filters and not bothered to re-engineer the computer air intake monitoring devices - then had all sorts of problems with their cars.

Basically it is my opinion that all those factory engineers know a WHOLE lot more than "the guy down the street" and the closer to factory specification you keep your vehicle, the better gas mileage you will get...

[CCc girl]

Make sure you save ALL of your original equipment air cleaner parts so you can reinstall them when you need any warranty work done, if they see the K&N it will void your warranty.

[ramkobe]

Exactly.

If K&N Filter and Slick 50 really increased fuel mileage, every auto manufacturer would install them on their cars as a cheap way to meet government mandates for higher fuel efficiency without having to spend billions actually designing fuel efficient cars.

They are nothing more than snake oil.

[KurtAZ]

Originally Posted by MckinneyOwnr

Now go buy an OEM filter and reset it again. I bet you'll get similar results. You can't test an old filter vs a new one and expect it to be a fair comparison.

I'll have to try that...although I changed out the Air Filter (OEM) last oil change...was still hovering around 29. I was just impressed to see it go over 30. Time will tell I guess.

[Billy_J]

Actually for valid results, these tests need to be "scientific". That is that the ONLY thing changed is one thing.

So same exact gasoline, same temperature and driving conditions outside. A/C on or not on for both tests.

Drive same exact route (with a test track you could have the same amount of stopping and starting to simulate stop and go traffic).

Drive same elevation - higher up has thinner air.

Etc.

[Billy_J]

P.S. Would you buy that filter if it came in a black plastic box and looked like a factory air filter?

Is it possible that a plain looking air filter in a black plastic box could work better than a fancy looking air filter?

[MckinneyOwnr]

Boy there's a lot of misinformation in this thread. K&N filters can make a difference on just about any stock car. The reason?

The stock airbox is designed by all those engineers that work for these auto manufacturers to be quiet. If you buy a full K&N system, you're ditching the stock airbox and usually enlarging the intake piping with smooth piping, rather than the factory rubber hoses which usually are designed to slow down the air velocity a bit, also for noise and emission levels. In short, an aftermarket K&N system can add horsepower, and also increase gas mileage... if you don't drive it any differently than you did before. The engine is working less hard to draw in air than it did before.

Now, in the case with a simple filter swap, the results are generally negligible, except in the case where someone replaces an old dirty filter with a new K&N. That's not a fair comparison to make.