Interesting tests on Air Filters such as the K&N

[Executioner]

Don't know about you guys, but I did buy a K&N for my 2001 Ford F150 and used it for years. With the advancement of internet information, here are some facts regarding several filters:

http://www.nicoclub.com/articles.php?id=180100

Compared to the AC, the K&N “plugged up” nearly 3 times faster, passed 18 times more dirt and captured 37% less dirt. See the data tables for a complete summary of these comparisons.

Anybody here using a K&N? Their argument has logic behind why its better to use paper:

Now I am not saying that ALL aftermarket filters are useless. A paper filter does not do well if directly wetted or muddy. It may collapse. This is why many off-road filters are foam. It is a compromise between filtering efficiency and protection from a collapsed filter. Now how many of our vehicles collapse their filters from mud and water?

However, if a filter is using "better airflow" as their marketing tool, remember this....Does it flow better? At very high airflow volumes, probably. BUT, our engines CAN'T flow that much air unless super-modified, so what is the point? The stock filter will flow MORE THAN ENOUGH AIR to give you ALL THE HORSEPOWER the engine has to give. And this remains true until the filter is dirty enough to be recognizeable. At that point performance will decline somewhat. Replace the filter and get on with it.

and this site:
http://home.mindspring.com/~ed_white/id5.html

with this statement at the end:

"MYTH BUSTERS
"A dirty air filter. Our tests show that driving with a dirty air filter no longer has any impact on fuel economy, as it did with older engines. That's because modern engines use computers to precisely control the air/fuel ratio, depending on the amount of air coming in through the filter. Reducing airflow causes the engine to automatically reduce the amount of fuel being used. Fuel economy didn't change, but the Camry accelerated much more slowly with a dirty filter."

[DoPeY5007]

Hmm, I did put a K&N in the wife's Civic Hybrid a few months back....

[Err]

Interesting articles. I haven't had any trouble with K&N filters. However, I'll probably never buy another one if these tests are confirmed. I'd always wondered about Air Filter vs Fuel Economy because I've never noticed my economy go down with a dirty filter. I would like to see more washable filters though. This is one of the reasons I bought a K&N in the first place. I know there are others out there but I haven't tried them. I think Fram and AEM both make one.

I currently have a dry cone filter on my CAI. It's the one that came with the setup (I'm pretty sure it's an AEM but stamped MOPAR). It's been on the car for over a year and my economy has been the same. By the way, CAI's don't increase Fuel economy either. The engine has slightly faster pickup and a nice growl but that's it. The only reason I put it on in the first place is that I broke one of the stupid plastic clips off of the air box and didn't want to spend the money replacing it.

[Lmandrake]

If you look at K&N's own claims for hp increases you see that the biggest gain is at the highest end of the rpm range. So the product only offers an advantage to the user who is regularly thrashing the living s**t out of their engine.

I like to beat on my cars once in a while. A performance filter does me no good when the car hardly ever sees more than 3500 rpm.

Unless you get really serious and start spending some serious dinero, most aftermarket performance parts don't get you jack...

[Err]

Unless you get really serious and start spending some serious dinero, most aftermarket performance parts don't get you jack...

I tried to tell someone that on the Dodge Avenger forums when they wanted to buy a larger throttle body. I told them the money would be better spent on an intake and exhaust and even then you're only looking at 10hp gain at best. A larger throttle body isn't going to give you jack without forced induction and a tune. Horsepower is expensive.

[Key Keeper]

Horsepower is expensive.

The old golden rule will never die

"There is no substitute for cubic inches"

....then again the bottle and blower/turbo guys will always argue with it.

[normalicy]

LOL, there's a big post about this on my Jeep forum. Jeep guys won't touch the K&N filters because there's always dirt on the inside of their intakes after an outing. I've NEVER noticed an appreciable difference from a filter, better plugs (so long as the ones they replaced weren't on their last leg), Throttle body spacer, or high flow cat.

My Jeep magazine even went through & tested everything under the sun for both power improvements & economy improvements. They basically said that except for exhaust upgrades, computer chips (they were surprised), & major engine modifications, there weren't really any performance mods worth the price of entry (yes, they dissed on some companies that advertise with them, which is why I subscribe).

On my Jeep, the only things that made it go (I could feel the difference) were headers (Borla), Cat back (Borla), 4 barrel carb (good for power, bad for fuel milage), MSD ignition (smoothed idle added a bit of power/fuel economy, also reduced pinging with cheap gas). Everything else is a major engine change.

[Executioner]

I'm just mainly concerned with the MAFS (mass air flow sensor). On the Ford forum, people have been having issues with using the K&N, because if you over oil the filter, the oil will contaminate the MAFS and reduce your mileage.

[Pugsley]

Same thing with the TDI forum. Stay the hell away from the K&N. It will mess up your MAFS and does not help anything unless your running rocketchip stage5+.