vp911

Please excuse my ignorance here. What exactly does the K&N filter do for you? How often do you have to replace the normal filter? From what I understand the K&N is reusable, correct?

ASP

http://www.knfilters.com/filtercharger.htm

ASP

Our Air Filter -> http://www.knfilters.com/search/prod...x?Prod=33-2299

Rich in NC

I am not a big fan of K&N air filters. I have seen too many cars with dust in their intake.

Take a lokk at this test. Most modern cars get plenty of air. It is a very easy factory design and it would be a huge step backwards to short an engine on intake flow.


http://www.bobistheoilguy.com/airfilter/airtest3.htm

also:

http://home.usadatanet.net/~jbplock/ISO5011/SPICER.htm

vp911

Thanks for the info guys. I skimmed through the link you posted and will not get it. I was really just curious over anything else - but probably would have bought it if it wern't for you.

ASP

Have you ever seen a car's engine destroyed because of dust in the intake? I have not.

K&N type filters are VERY popular in many racing/street applications and I have never had a problem running one on any of my vehicles.

There are thousands of articles out there showing nice HP gains and MPG gains using K&N filters and K&N cold air kits.

I wouldn't let a couple articles based on particle filtration discourage you. As long as you aren't sucking up rocks and small creatures, life is good if you can squeeze a couple more HP and MPG for $35.

andrewgg2

I have used K&N air filter in my CL-S for 5 years. I did clean the filter every year. I had never had any issues! Now I have one in my RL. I am getting better MPG, not sure abut HP. They claim from 2% to 4% increase. Most of those Test's show different filters, I would like to see a test of K&N Filter vs. RL's Original Filter.

vp911

What has the diff in your gas mileage been?

Rich in NC

I would like to understand how a filter is going to make an MPG difference in a fuel injected engine with a closed loop system like the RL has. The trim tables are are only going to add enough fuel (injection pulse width) for the air available to produce an optimum fuel to air mixture. In the old days a carb engine would run too rich with a clogged or inadequate filter and reduce MPG.
Those days are gone.
I, litteraly, saw 100's of dyno runs on Corvettes and never saw an increase or decrease in HP with a filter change. If your car is geting adequate air you'll need to pressurize it to do any better. As far as a less effective filtering filter why bother? More money, and maintenance for what?

andrewgg2

I suggest you email K&N or Acura and ask, please post the reply. From my test, I did see better MPG in my RL. Before K&N air filter I was averaging 19.8 now I average 20.6.
Do you know any thing about HP increase? They claim 2% to 4%, so from 6 HP to 12 HP. I have not seen any tests. Let's say it was 3%, so 9 HP for $35 is well worth it for me.
Bottom line, I do not keep cars for more than 5 years so extra dirt in intake will not hurt me at all. I could care less what happens to the car after that.

Karl_in_Chicago

How many miles did your old filter have on it when you switched? Just putting in a clean filter can have the MPG effect. Just because K&N claims a HP increase doesn't mean it's true. Did you dyno before and after? That's the only way to show a real, measureable, increase. There's simply no way an air filter is going to provide a 3% boost to HP. As long as you are happy with what you've got, that's great, but that doesn't mean the rest of us are all going to cheerfully drink that kool-aid.

Rich in NC

E_mail Acura about what? That they would suggest I replace a well designed OEM filter with a filter that has shown to pass more particles. Did you even read the 2 independent tests?

Question for you how, in the world, did you find a driving circuit that would allow you to the limit the variables enougth to .8 mile MPG variation was filter related?

Since you haven't even seen any tests why would we assume any HP increase?

Bottom line... You are willing trade an oem designed filter for unknown if any gains for a filter that has been shown not to be very efficent?

agroves

K&N is not an unknown. If anything they are the standard when it comes to increasing air flow efficiency. You don't need to be a test laboratory to accurately assess power gains or gas mileage efficiency. If you need to understand what K7N filters do versus the others- go to a retailer and ask if they have the filter comparison demo. You can put your factory filter in versus the K&N. K&N Rocks- if it lets microns more of dirt in the ending but yields more power and efficiency- who gives a crap. Moisture content in the air can have more of a factor on engine life than the miniscule differences by the listed "Independent" articles. PS- His methodology of identifying oil versus dirt is borderline moronic. Let me take oil with a concentration of filters dirt particles, mix it with still colored and pure red K&N recharge oil and see if the concentrated dirt dissipates. Are you really buying that? I put K&N filters in my MDX, RL, A6-4.2 and even my 4 wheeler- single cylinder, 440 cc 4 stroke engine that produces 50 hp- and have yielded HP and gas mileage gains in every one of them. In my RL specifically- the computer automatically adjusts fuel mixture to the increased airflow. I have seen noticeable increases especially in the much needed low end torque/power. To really get the 300 HP out of the 3.5 you have to shift at 6000 rpm. Anything that assist me in not running the engine at 95% of redline is far more valuable than concentrations of dirt in combustible oil.

Sorry for being so passionate- it is late and I couldn't take the banter any longer.

PS- K&N has a performance grantee and if you blow a motor and can demonstrate that you cleaned the filter, I am confident they would be hard pressed not to assist in the repairs. Of course, that would have had to happen in the hundreds of thousands of air filters they have sold and not one claim against them for bad motor. Huh, makes you think.

ASP

agroves

Rich in NC

I guess we are going to have to agree to disagree, They only things I have seen are dirtier intakes, dynos that weren't impressed, and people thinking they have gains that just get down to a louder intake noise. If further airflow would make a difference on a stock Acuras, Honda engineering would do it in a heartbeat, Do you think they spent all that that money on everything from variable timing to dual exhaust outlets and, super fast computers just to blow it on a simple filter size and media type selection? I am going to guess you have never seen a flow bench and other tools engineers use to design and perfect modern engines.

agroves

I haven't and don't need to. I can easily understand that there is no manufacturer out there that wants to put an air filter in a car that requires maintenance when the precedence is throw-away paper. The K&N needs to be oiled to work properly. The traditional consumer doesn't want to do any more than necessary. I imagine competitors would jump on the standard use of K&N like filter technology as "high maintenance, tricky, messy..." K&N has very good copy write protection on their product and they won't sell to manufacturers as they are still considered the stock alternate for performance minded people. The mere point that we invest time on this site to gain a better understanding of our RL's clearly demonstrates we are not the typical end user and I think a glowing endorsement of the K&N is appropriate to this forum.

Rich in NC- I respect and applaud all of your other posts that I have seen on this site. This one I am sorry, but can't go your way. IF you keep your car for 15-20 years, don't try it. But if you don't which I suspect- give it a try and let us know if you really don't feel, hear or see a difference.

spacklebucket

In a Civic, sure.....why not try to get a little better air flow. In a $50k car, I'm not sure I can justify the time it would take me to change the filter. I also need to question how there is any way an air filter could give you better gas mileage. Let's assume for the sake of argument that the airflow is increased by changing the filter. Wouldn't the MAF sensor detect the increase in air flow and cause the ECU to subsequently add MORE fuel to compensate? More air flow normally warrants more gas flow. Unless there is something different about the RL that I'm not aware of.....

Rich in NC

I have been into racing, dyno testing and tuning, high performance instructing, and generalling messing with cars for over 40 years. I have seen hundreds of dyno tests and have spent countless hours tuning cars for max output. I have used every kind of filter known to man and have spent lots of time switching out different air systems. It's just a simple fact that once a stock engine sees enough air flow a bigger or more open filter is NOT going to make a difference. A sloppy one will allow more dirt (mostly silica in most parts of the country) into the engine but it isn't going to make more power. My guess is what you think you are feeling is more intake noise which does not translate into more power. In fact most dyno tests will not show more power with the filter completely removed in a decently designed system.
Again, don't you think Honda engineering with a zillion dollars in flow testing is going to design a system with a enough surface area and media type to provide sufficent air? It's not rocket science, And it's not a matter of sticiking some oil on some foam rubber.

Rich in NC

That is a very logical question. More airflow means more fuel consumed.

1HOT NSX

My

Any type of aftermarket filter - including K&N - is a waste of money and a downgrade from the OEM filter. More horsepower and better gas mileage are illusions, the only thing you get more of - is noise - and not the intoxicating and sweet type of noise like the NSX intake makes at 8K RPM but just plain ugly noise. I've reached this conclusion after using these filters (including K&N) in many cars as I grew up through the stages of lower suspensions, turbos, Eibach springs, "sport" (read noisy) exhausts, etc. etc. All the stuff that you must have on your car as you grow up.

frenchnew

Rich, as much as we try to steer people in the right direction, they prefer to believe Company's Marketing Claims.

Like you, I have seen dirtier intake on engines using the K&N filters. Even had a customer who had asked me about it before he ignored my reccomendation and bought one for his Ford pickup. After 3 years and roughly 100,000 miles, he called me and told me that even if he was cleaning out the K&N and re-oiling it frequently, it worned down his engine to the point that there was not enough compression for it to run and the oil comsumption had surpassed the gas comsumption.

On point of notice on the second link, they point that they are using PTI Corse Test dust as per industry standard and this is totally wrong. Most serious filter manufacturers use PTI Fine test dust for their Air filter tests.

And for everybody's information, K&N is not a manufacturer of filters. They have them made by someone else and the same applies to AC Delco, Motorcraft, Amsoil.

Best regards

frenchnew

agroves

OK- You all make good arguments. Racing- dyno... I concede. I do subscribe that K&N lets more dirt particles through- just believed it to be minor.

I know it is louder and agree with the notes- it isn't a clean powerful sound- instead just a louder one.

IO have seen dyno test of pre and post K&N filters on Motorcycles and ATV 4 stroke engines- they are noticeable and really felt the difference at low end. These types of dyno's- I suspect, are much cheaper than AWD auto dyno's.

You have given me cause to think/rethink- for that I thank you. Not sure if I am fully converted but am humble enough to pause when presented with plausible arguments.