So which air filters are the best????
 

I thought I saw metrompg post a pic of all the filters and it was so weird brand that was the best.

My air filters keep getting dirty too quick. After 5-6k I have to get a new filter. Any recommendations??? I can get a new nissan filter for about $7.50 but they get dirty quick and so does the Fram crap. My engine sucks in air like crazy.

If you get a worse filter it
 

If you get a worse filter it will take more time to get dirty.

Re: If you get a worse filter it
 

so I'm getting the best filters?

Possibly. I friend with a
 

Possibly. I friend with a f150 found a dyno test with 12 filters and ac delco was the best and k&n was the worst. And metro's graph confirms the bad filtering capabilities of the k&n (if we are to believe it).

Re: Possibly. I friend with a
 

but did the ac delco filter out good?

It's considered an OE
 

It's considered an OE replacement, I believe, so it's around the stock filtering quality. I just hit my dirt out on the driveway and it's mostly all gone, :p

So if my nissan filter gets
 

So if my nissan filter gets dirty after 4-5 months and I see the best mpg with it then I should keep with it?

also what could be causing it to get dirty so fast, even if it's good at filtering something else must be wrong?

I can't honestly say why so
 

I can't honestly say why so fast. Mine's sposed to be changed every 15k miles, and I haven't even looked at it since I first bought the car, mehbe I will.

I'll be changing my engine
 

I'll be changing my engine temp. sensor which control closed loop, amount of fuel being dumped, when the fans turn on and off and some other things I don't know about.

Maybe the sensor has something to do how much the engine sucks air???

I have a sweeeet foam filter
 

I have a sweeeet foam filter simaler to what amsoil used to sell, they now sell a "micro fiber" filter that you just blow out with compressed air that is suposed to do as good if not better of a job at collecting dirt then normal paper, with a higher air flow, or so they say.
I haven't noticed any differnce in mpg gains with paper over the foam, but I like that I can wash my foam filter, re-oil it, and not have the cost or extra trip to the store to buy a new one.