Quick question off the topic of motorcycles.

I was looking at air filters for my car and I was thinking about buying a K&N filter instead the el cheapo filter that I normally get.  My car has 55.000 miles on it.  Are they worth it? and will it help on gas mileage?

Thanks,
Jeff

the good thing about K&N is they last a lot longer then other filters...so if you plan on driving your car for a long time then it will pay off....

if your normal air filter is about $5 and the K&N is $50 then in about 50 000 miles the K&N will pay off since you don't have to replace it with a new one...

Depending on your car, it might increase mileage, but nothing too substantial. Don't expect any major changes on your car from just an air filter. Remember, the entire path your air takes into the manifold is still the same.  The one thing you will most likely notice is a slightly better throttle response. To be honest with you, unless you are doing a number of performance mods (Air intake system, Headers, Exhaust) It's not really worth it to spend the $40-$60 on a K&N filter. What kind of car do you have?

OK-

I went about the mods to my car in a methodical manner.  Doing them ome at a time to see if they made an individual difference.  It ran good, but after adding the K&N it ran much better and picked up a couple miles per gallon.  They are easily worth the money, and if they made a full K&N intake system for my car I'd but it because they are truely a well engineered product.  On a normally aspirated engine, pumping losses are what limit the engine's potential, and the filter contributes greatly to the restriction.  Additionally, the filters do their job very well, and the resuable aspect of the K&N is a great bonus.

Consider the Amsoil filter too. It flows about the same as the K&N, is still reusable, and traps more crap.

it's worth it.  they aren't that expensive.  i picked up on average 2-3mpg when i put one in my beater.  of course, that was going from a dirty air filter to a new k&n one.  probably would have seen some improvement replacing the dirty one with anything.  the filter better anyway, even if there isn't a major performance gain.  i have one on my supra too.

I ALWAYS run a K&N in my vehicles.  There is no reason not to.

i run the K&N drop in on my ford focus..

it made the car throttle response a lot better.. and picked up maybe an HP or two. However gas mileage went up by 2mpg..

and as for cleaning it. I think the K&N sends more air in.. i wanted to clean the filter the other day and noticed only the side that was under the inlet was black the other side was pink so i just turned it around and now its like i got a new filter. I will wait for it to turn black too before i clean the filter.

Umm...Good Guy.  That is probably not a very sound practice.  That dirt is not held to the filter very well, and the intake vacuum will suck it off and into your engine.  There is a reason for a clean and dirty side.  Often with panel filters there is a flat and a pleated side, with the pleats being the outside intake.  The pleats add surface area to increase airflow while still being able to effectively filter.  I would reccomend cleaning the filter immediately and reinstalling it correctly for the sake of your engine.

anyone know if they make an inteak/filter assembly for an older 87 GT escort...? 1.9 EFI motor....

He did not swap clean side to dirty side... His filter like many others can be rotated into any position. He had a spot that was dirty cos all the intake air is going through that spot. He moved that spot away from the point where flow is happening so it now goes through a clean spot.
Cool.
Srinath.

Quote from: seshadri_srinathHe did not swap clean side to dirty side... His filter like many others can be rotated into any position. He had a spot that was dirty cos all the intake air is going through that spot. He moved that spot away from the point where flow is happening so it now goes through a clean spot.
Cool.
Srinath.

thank you srinath.. that's excatly what i did.. just moved the blackend spot to the other side of the airbox..

Thanks for all the replies.  CasiCUA, I have '92 Olds cutlass cierra, it has a 3.3L V6, so the gas milelage isn't the best.  And any imporvement would be welcomed.

One thing I do not fully understand about the K&N filter is how it is able to give more horsepower AND better gas mileage.  Anyone have ideas on how this works?

With an improved filter, the engine does not have to work as hard at any given RPM to draw in the air needed for combustion.  So, it can provide the same power output as before at a lower RPM.  Gas mileage is only really improved if you can keep your foot out of the fun pedal, but the increased power (albeit a small improvement) should always be there.


Good Guy-Sorry about the confusion with your post.  A buddy of mine did what I described in my post to a car that I sold to him and it was in the junkyard within six weeks, so its a real sore spot for me.  In the back of my mind I thought that you may have just rotated the filter, but I forgot to put that in the post.

Quote from: Jace009anyone know if they make an inteak/filter assembly for an older 87 GT escort...? 1.9 EFI motor....

knfilters.com, you can search by vehicle.

I really don't think K&Ns actually filter that well. They flow more air, but I think they flow a lot more dirt as well. There are pretty big openings through the filter material if you look at it with a magnifying glass.

I was doing some research on engine wear mechanisms in the SAE paper library, and it turns out the airfilter is far more critical for engine life than the oil or oil filter. Engines suck in a lot of air, and if it isn't well filtered they eat a lot of dust too. Some of that makes it into the oil and the engine wears more quickly.

I have a K&N on my Honda, but only because it was there when I bought it. I keep meaning to take it out, but it does make a noticeable performance difference.

Oh, one more thing: changing or cleaning your airfilter too often is actually bad for your engine! Airfilters filter more effectively, and finer particles, when they are dirty. Of course perfomance suffers, since the filter doesn't flow easily, but it's a trade off.

Yup... With a K&N anytime you open the throttle you sand blast the top of the piston. Anyway made 45K on the GS, 25K of it with the K&N and in 25K I dont think its gotten much worse than if I had paper or UNI. But I get the idea. This friend of mine has a 75K GSXR with K&N's on it for 45K+ miles. Its a little bad for the motor I am sure but nothing to worry about too much. Rust or a crash or boredom will kill your GS before K&N's do.
Cool.
Srinath.