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.

Re: I have a sweeeet foam filter
 

Do you have a link where I can get one???
I used to have an Injen filter, it stayed clean but it let in too much air and my car compinsated with more fuel. Do these filters let in a lot more air?

I replaced the Prius filter
 

I replaced the Prius filter at about 45k miles. I kept it clean by using a shop vac to remove the dirt every 5k miles or so.

The Del Sol filter was clean when I bought it and 4k miles later it is still spotless. Im wondering if the left coast is dustier? Maybe it's the smog?

Re: I replaced the Prius filter
 

I doubt it's the smog. But I don't know what it is. Like 100 miles ago I had to flip the filter because the spot that absorbs the most air was black. The whole filter doesn't get dirty, only the spot where the air passes to go into the MAF

Re: I replaced the Prius filter
 

When you say black, do you really mean black or gray or what? Can you lighten the color with suction from a vacuum cleaner or does it stay the same color. I'm thinking it might be oil or something else being picked up at the intake.

The intake hose goes to the
 

The intake hose goes to the left headlight and sits behind it. So when air goes under the headlight it finds it's way to the intake hose. That spot behind the headlight is clean. The filter is gray. Can't be cleaned off with a a vaccum.

Intake Restriction vs. FE
 

OK, so I hear that replacing a dirty filter will improve FE; however, I have a restrictor device that blocks the flow of intake air considerably, and I seem to be getting better mileage due to forced, slower acceleration. Am I killing the potential for better FE on the highway?

RH77

a air filter is already a
 

a air filter is already a good restrictor. Performance air filters like K&N, Injen, and etc let too much air in and the engine compansates with fuel. Just use oem filters which have more restrction but they give the best results.

I was just looking for a filter that would filter out the same as the nissan filter but get dirty slower.

Re: I have a sweeeet foam filter
 

I want to start this reply by saying that I am NOT an Amsoil dealer but am what they call a "preferred customer." This means I get a price break but don't make any profit. That aside, I can look up a price for the new Amsoil filter if you would like. I have to eat supper now so I'll post some prices in a little while.

Re: a air filter is already a
 

Really Complicated. Spend some time at the store counting the filter pleats of the different brands that are offered. The more pleats, the slower the filter will get dirty.

is it hard to change an air
 

is it hard to change an air filter these days?

Quote:is it hard to change
 

Did my friend's 03 civic and it was a piece of cake. 4 screws.

The cost for an Amsoil air
 

The cost for an Amsoil air filter for a '99 Nissan Altima is $26.00. They are good for 4 yers/100,000 miles. It works out to about $9.53/year over it's lifetime.

Re: The cost for an Amsoil air
 

The important question I have for you is are you using an Amsoil air filter???

And how long you had the same filter in your car and how often you clean it and how you clean it?

I clean my foam filter every
 

I clean my foam filter every time I think of it, about 5,000 miles, and have a paper filter that I slip in when I'm cleaning it as with foam filters you wash it with soap and water, dry it, and re-oil it with high-tac filter oil, so it's best to have the filter out of the car for a few days.
I personaly like the idea of the foam, it has a few differnt layers, going from corse to fine, and I figure it must be doing a good job of getting grit out, as the car still has 185psi + or - about 5psi acrose all the cylenders, and it's the origonal engine with 221,000 miles, and have found that useing foam filters on my motorcycles leaves the carburators much cleaner, as I understand it, foam filters are not standerd because they cost a little more, amaricans don't like things that are washed, and reused (recycle your bottles, don't buy returnable) and there is less to mess up if you just replace the part with a new one.
I can't tell exactly how much restriction it has, as I don't have a good way to compare it, the printing on the filter is gone now, but I think it was something like a True-Flow, only it doesn't look exactly like what they are selling now under that brand name.

Re: The cost for an Amsoil air
 

Yes, I got one of thier foam air filters soon after I got the car. I have cleaned probably 3 times.(?)

Re: Intake Restriction vs. FE
 

Yes, I'm quoting myself -- any ideas on air restriction before combustion vs. FE???

Re: Intake Restriction vs. FE
 

It sort of makes sense. With increased velocity of oncoming air I think it may promote swirling in the cylinder. Air rushing in so fast may slam against the opposite side of the combustion chamber and cause turbulence? :? I suppose it's possible that there could be a limt to how much you could restrict airflow before FE could start to drop.

May have to experiment
 

I may do a small experiment to see what works -- it seems to be a lot like exhaust backpressure, which varies by car and isn't fully understood. All kinds of advice from the EPA on down to the filter manufacturers say to change the dirty air filter and get better gas mileage: read restriction. I might try a small trial this week to see what happens (depending on the weather -- lots of rain predicted). The current restriction is down to about the size of a quarter with air temps ranging (I really need a grille block) -- and I've maintained MPGs in the low-30's. It definitely requires more pedal pressure, which the auto-trans doesn't agree-with on really hot days and/or with the A/C running.

RH77

hmm i have a high flow intake on my truck... i wonder if i put back my stock air struff i would see better MPG. (im getting 25mpg witha 2.2L 5speed s-10) deff worth a try IMO

I'd be interested in the results :thumbup: