Possible 6% mpg gain from adding a cone filter...Ford Focus...

[MPGranger]

Originally Posted by t vago

What caused the improvement? Removing the cold air inlet? Removing the resonator? Changing from a probably dirty filter to a likely clean filter? A combination of all 3 actions? What?



So.... in other words, you don't know whether IAT has changed.

The EPA has done studies and found out that a dirty filter affects power not FE
http://www.fueleconomy.gov/feg/pdfs/...02_26_2009.pdf

But changing out the OE tiny little air tubes for the cold air intake vast gaping cavity vastly improved airflow. So more air means better volumetric efficiency. And if you P&G, more power means getting to speed sooner, which translate to more gliding and less pulsing.

[Mustang Dave]

This mod only helps FE if you're using fuel line magnets.

[niky]

It will help if it changes the MAF signal in the right direction. Aside from turbulence factors, air filters sometimes cause the engine to lean out slightly, as the ECU is receiving more air than it thinks it's receiving.

Air filters can and sometimes DO change economy. The problem is they usually do so for reasons that have nothing to do with the filter media and everything to do with the shape of the filter and the filter installation.

[mechman600]

Originally Posted by niky

air filters sometimes cause the engine to lean out slightly, as the ECU is receiving more air than it thinks it's receiving.

Until 0.0000001 seconds later when the ECU sees the O2 sensor value change and makes a fuel trim correction, netting absolutely no A/F difference at all.

[suspectnumber961]

Someone posted that he saw an mpg gain from this on a forum dedicated to the Focus...took me a long time to try it due to believing it had little chance of working. I already had what I thought was a good flow...don't exactly run the car a full throttle a lot...taxing the intake system. You can buy these cone filters at parts stores for not too much (the off brands)...installing it like I did means it is easily reversible.

All the brilliant analysis as to why it won't work is FUNNY. Just like watching people TAKE A DUMP.

cons? Noisy if you floor it...not the best filtering in a dusty area?

I wouldn't want to encourage anyone to improve their mpg...it's like pushing drugs.

Originally Posted by HydroJim

Please do more testing because if this is true, I'll have to install one of these on my focus.

[niky]

It depends on the car and the filter. It is not that instant, as it requires the O2 readings to wander significantly in closed loop running. Won't affect idle, WOT or anything else, not unless the discrepancy is so big it throws the long term fuel trim completely out of whack and the car starts to adapt over the next few hundred miles.

And even then, with the limited fidelity of narrowband O2 sensors that come on most cars as stock, sometimes, the car can't adapt. Or, it maladapts, which is how the Mazdaspeed brand CAI causes CELs on the Mazdaspeed3 and 6, and how certain cheap aftermarket filters with MAF adapters cause Subarus to blow up.

The better modern brand name filters and CAIs are tested extensively to ensure they don't cause the LTFTs to wander, even when they lean out the intake charge.

[mcrews]

look, you have 281 posts, so you have been here awhile.
Let me be blunt.
you'tr not a neebie.
post up an aba test or take the wrath you have coming.
What's funny is your clueless post.

[suspectnumber961]

Well...you can't have it both ways? Time will tell...no point in arguing about it.....

1st tank I thought it was a refill issue...but gas gauge is accurate at 1/2 tank mark vs trip meter....looking like the gain will stick.

I do A-B tests only.

I'm not a newbee...but I am clueless!

Originally Posted by mcrews

look, you have 281 posts, so you have been here awhile.
Let me be blunt.
you'tr not a neebie.
post up an aba test or take the wrath you have coming.
What's funny is your clueless post.

[MetroMPG]

mcrews is referring to this idea:

http://ecomodder.com/forum/showthrea...ery-11445.html

(Members who have been around here a while should by now expect skepticism in proportion to the validity of the testing method used.)

[t vago]

Originally Posted by suspectnumber961

All the brilliant analysis as to why it won't work is FUNNY. Just like watching people TAKE A DUMP.

I'm not saying that you didn't get a 6% improvement because of your filter.

I'm saying that you have no clue how your filter installation caused that 6% improvement. Furthermore, I'm saying that your guesswork (you did say "IAT is probably close to the same as before...around 10F higher at 70F...3-4F higher at 90F vs ambient....so it's not likely a warm air issue.") isn't helping matters any.

You need to be more rigorous in your statements. It's fine that you make initial observations, but you need to be able to back them up with verifiable data. Otherwise, as another poster pointed out, you might as well be installing fuel magnets.