Talk some sense into me... :-)

[rvanengen]

I was getting ready to stop by the parts store and get a new air filter for my wife's 2003 Taurus, when a thought hit me...why bother?? Unless the airflow is completely blocked, it should have a 0% effect on fuel economy.

Now, here is my reasoning (if you can call it that)...since the car is a full ODBII car, it will constantly adjust for the amount and density of air that is coming into the car, and given that, it cannot run rich (except when warming up), regardless of the airfilter. Now, in the days of carbs, the air filter made a HUGE difference...but not anymore, me thinks...

[ezeedee]

my filters get dirty pretty quick, but i do take it off-road and i drilled holes in the lower air box and removed the snorkle. i probably clean it off about twice a month (just smack it against the ground) and replace it twice a year or so.

i have a spare air filter i throw in when i go off-road though, so the daily one doesnt get abused too bad.

[ezeedee]

Originally Posted by theclencher

What'd ya do all that for? Didja think the factory boys don't know what's going on?

I credit the snorkel design on my F150 as one reason for why the filter stays so clean for so long.

it sounds nice and gives it a little more power. my truck is a dog, and the bigger tires dont help much.

[Mike T]

If it's a cold air intake that you removed, it would have been better with it in place!

[ezeedee]

Originally Posted by Mike T

If it's a cold air intake that you removed, it would have been better with it in place!

i can definatly tell that there is more power through the rev range. the snorkle was pretty restrictive, had all kinds of valves and flaps inside to let exhaust gas in, etc... the downside is... it sounds nice, so i have to try that much harder to keep my foot out of it, but its nice to have the power when i need it.

[Greybrick]

Originally Posted by rvanengen

I was getting ready to stop by the parts store and get a new air filter for my wife's 2003 Taurus, when a thought hit me...why bother?? Unless the airflow is completely blocked, it should have a 0% effect on fuel economy.

Now, here is my reasoning (if you can call it that)...since the car is a full ODBII car, it will constantly adjust for the amount and density of air that is coming into the car, and given that, it cannot run rich (except when warming up), regardless of the airfilter. Now, in the days of carbs, the air filter made a HUGE difference...but not anymore, me thinks...

Easy enough to check the hypothesis with a scanguage, cover about 3/4 or what ever percentage you like of the filter with a sheet of plastic and see what the mpg is. On a really dust free day such as after a rain on a traffic free highway the reverse check would be to remove the filter and freeflow the intake by putting on something like a sheet of open-cell foam so you aren't pulling in insects and small rocks and again with the scanguage see what your mpg is doing.

You'd probably want to do something like 50 miles so that the ecu has a chance to reset if it has to and do both tests on the same stretch of road under similar conditions, time of day, temperature, alignment of planets, etc. I won't give away the answer as it's more believable when you see the results on your own vehicle.

Thinking of all this, I wonder if installing a 2" thick section of free flow open cell foam in front of a flat filter and cleaning that every once in a while would increase the paper filter's life span.

[rvanengen]

Originally Posted by Greybrick

Easy enough to check the hypothesis with a scanguage, cover about 3/4 or what ever percentage you like of the filter with a sheet of plastic and see what the mpg is. On a really dust free day such as after a rain on a traffic free highway the reverse check would be to remove the filter and freeflow the intake by putting on something like a sheet of open-cell foam so you aren't pulling in insects and small rocks and again with the scanguage see what your mpg is doing.

You'd probably want to do something like 50 miles so that the ecu has a chance to reset if it has to and do both tests on the same stretch of road under similar conditions, time of day, temperature, alignment of planets, etc. I won't give away the answer as it's more believable when you see the results on your own vehicle.

Thinking of all this, I wonder if installing a 2" thick section of free flow open cell foam in front of a flat filter and cleaning that every once in a while would increase the paper filter's life span.

I might have to ask you to cheat and tell me what your experiences have been since I don't have a SG...but I am gonna guess that unless the car runs open enough throttle to need more airflow than the filter can flow, that there should be no effect. ???

[Bill in Houston]

Originally Posted by rvanengen

I was getting ready to stop by the parts store and get a new air filter for my wife's 2003 Taurus, when a thought hit me...why bother?? Unless the airflow is completely blocked, it should have a 0% effect on fuel economy.

Now, here is my reasoning (if you can call it that)...since the car is a full ODBII car, it will constantly adjust for the amount and density of air that is coming into the car, and given that, it cannot run rich (except when warming up), regardless of the airfilter. Now, in the days of carbs, the air filter made a HUGE difference...but not anymore, me thinks...

I have the exact same thoughts. Change it for power, but don't expect mileage to go up.

[trebuchet03]

Originally Posted by rvanengen

I was getting ready to stop by the parts store and get a new air filter for my wife's 2003 Taurus, when a thought hit me...why bother?? Unless the airflow is completely blocked, it should have a 0% effect on fuel economy.

Ask yourself this.... "What is the primary function of your air filter - is it fuel economy?"

The answer should be no. The primary function is filtration. If it's still filtering well (and not clogged outright), you're fine. But, if it has become damaged (think of what sand does when vibrating against anything) - replace it.

A somewhat decent way to check is to look at the "downwind" side of the filter assembly - is it dusty? If it is, replace it (then clean the plastic) - if not, inspect and clean the filter, then put it back