Air filter

[Cheesypuff]

So the air filter on my car is getting a little dirty, i'm really tired of going to change my oil and have them tell me my air filter needs changing ($26), which i know is wrong, because i just changed the blasted thing. Anywho...do you guys use the disposable air filters? Or use the K&N never have to replace filters?

I'm thinking about going the never have to replace route, i think it'll buy itself back after around 3 years or so. What do you guys think? what do you do? what do you use? What do you recommend?

tia

[Daedalus]

Stock filters are probably always best. K&N does wonderful marketing to sell you stuff that, in the long run, may be harmful to the car. You still have to clean and oil the K&N filter don't you? That's muss and fuss I can live without. And the stock filter won't deposit oil on your air sensor, it has more surface area than the K&N, and it'll let less grit and dirt through that would wear the engine over time.

As far as the shop telling you that you need to replace it, ignore them and stick to the factory service interval. 15k, 30k or whatever it may be. Those guys at the oil change shops almost always have financial incentives for selling you stuff. What exactly is a visual test for an air filter? Never seen it in any of the shop manuals for the cars I own. How clean is clean? How dirty is dirty? Service interval is simple enough to stick to. Oh, and you can probably find an OEM filter from a wholesale dealership online. I buy a lot of things at once to spread shipping cost.

[uncledaddy]

Stock filters are probably always best. K&N does wonderful marketing to sell you stuff that, in the long run, may be harmful to the car. You still have to clean and oil the K&N filter don't you? That's muss and fuss I can live without. And the stock filter won't deposit oil on your air sensor, it has more surface area than the K&N, and it'll let less grit and dirt through that would wear the engine over time.

As far as the shop telling you that you need to replace it, ignore them and stick to the factory service interval. 15k, 30k or whatever it may be. Those guys at the oil change shops almost always have financial incentives for selling you stuff. What exactly is a visual test for an air filter? Never seen it in any of the shop manuals for the cars I own. How clean is clean? How dirty is dirty? Service interval is simple enough to stick to. Oh, and you can probably find an OEM filter from a wholesale dealership online. I buy a lot of things at once to spread shipping cost.
:stupid:
Daedalus is right. Those K&Ns can cause you more trouble than its worth. They can cause faulty MAF readings and performance problems. And they don't give any better performance than a clean stock filter. As Daedalus said, follow your manual, unless you live in a dusty climate like out in the sticks off a dirt road, then a little sooner. When the service guys say you need a filter, just politely say no thanks. :D

[renovation]

i dont know how many times i use to just take my air filter out. just tap them on the cement ,or use a air gun and blow the dirt out of them . then reinstall them and go for another couple thousand miles. sure that was when you just needed to remove a wing nut to lift the lid off the air cleaner housing. and other times we just turn the air cleaner filter a bit if the pcf valve would oil up the air filter in a spot.

[mechmike0034]

Filtering efficiency actually increases as the filter gets dirtier. The dirtier the filter, the more effective it is at collecting more dirt.

On the other side of the coin, more dirt = more air flow restriction.

Stick with stock, and replace it at manufacturer-specified intervals unless you run off-road or in extremely dusty/dirty environments.

My wife's car - a back-and-forth commuter with 150K miles on it - is on its second replacement. I changed it at 60K and 120K.

On a modern, computer-controlled (post-1996) vehicle, a dirty filter won't affect gas mileage until it gets so dirty that it begins to have an effect on engine performance.

Modern engine control systems meter fuel injection based upon temperature and humidity-corrected measurement of the actual air mass entering the engine. If less air enters, then less fuel is metered.

Only when the filter clogs to the point of causing an airflow restriction that is so large that the engine control system can't compensate will the driver notice a problem. Wide-open throttle performance will be affected first, since that is the operating condition which produces the greatest airflow.

More here: http://www.bobistheoilguy.com/airfilter/airtest1.htm