Snip-No, on that vehicle, it couldn't.

http://www.fueleconomy.gov/feg/pdfs/...02_26_2009.pdf

 

Not that I'm a sissy mary or anything like that but I will be wearing light gloves when taking the engine cover/air box off next time-the rim around the lower edge of the outer rim of the engine cover did a good job of multiple "paper" cuts...

 

Its a pain to change, but 60K on a filter is terrible on the engine. Imagine trying to breathe through a straw while jogging, now you know why the mileage is off par. And to second BlackknighT, wear gloves because that engine cover is sharp.

 

I noticed a mileage increase of a few points, as well as an increase in power, after changing mine at 23k, it was the factory filter and noticeably filthy....... Cleaned a bunch of leaf bits out of the "woolly worm" too..... that tube acts like a pre-filter for larger stuff. How leaves get into the inner fender well I couldn't tell you.

While that government report Spozo linked to may say it can't happen, I would disagree....

Government tells me lots of things that aren't true.

 

What controls airflow into an engine? How is air mass measured? Why is it measured? Answer these questions honestly and accurately, and you'll see why a dirty air filter can't cause a decrese in FE. Power output? Yes. FE? No.

K&Ns RULE!!

-sigh-

I guess I should just keep quiet.

 

No need to keep quite.....

Just that a dyno test wouldn't necessarily be the same as real world driving. If the power output goes down with a clogged filter, which we agree on, you push it harder to achieve the same performance..... when pushed harder wouldn't mpg also go down?

 

It really depends on the area you live in as to how often it needs changing. Here where I live, I only drive on dirt roads occasionally, and slowly. So I rarely am in dusty conditions. I really wouldn't have needed to change mine with less than 50k, but I didn't know the previous owner's conditions.

 

Saying it keeps power the same by adjusting other things, is like politicians saying they wont cut jobs or raise taxes to increase funds, they'll become more efficient. Well, you have to do something to get more money right? Either cut jobs or raise taxes. Same applies to this. To get the same power, efficiency must be cut, or to keep the same efficiency, power must be cut.

 

No. Under normal driving conditions the throttle blade limits the airflow into gasoline engines. If the air filter becomes so restricted that it becomes the limiting factor to air flow, then it "acts" as the throttle at that point. Effectively moving it down the air inlet tract.

If less air goes into an engine, less fuel is needed to keep the AFR correct. So no change in FE. How does the ECM "know" less air is going in? The Mass Air Flow sensor is mostly used for that, on that particular engine. Other engines might use Speed Density calculations and infer air flow based off of inputs from other various sensors, other engines still, might use a hybrid of the two systems. The end result is the same though. Less air in, less fuel injected.

The common thought is that the engine will work harder because you'll open the throttle more to overcome the loss of HP, but as you can see, the engine will only flow as much air as the greatest restriction will allow, and the ECM will only give it as much fuel as is necessary.

Hope that made sense.