On my way to EROCC's this weekend I did a comparison between a clean K&N and a paper air filter. The trip was to Athens from Auburn AL, same both ways. I did a very accurate method of reading how much gas had been used (filling up each time and topping off, look at meter:D ).

I found that the freshly cleaned and oiled K&N and a paper filter got JUST over 1 MPG difference. The K&N was the one that came out on top, but not by much.

My brother thinks that maybe this was just coincidence cause he says that with my computer controlled Tacoma it might take a long period to adjust to a new filter. I dont know, Im just reporting my results...

I wish I had an Amsoil to try...

I don't know about gas milage but they do flow a lot more air. i say a display at a parts store and it is hard to explain but it was a tube sitting on top of a box the box had a square hole to put either a k&n or another filter. The tube had a pingpong ball in it and a fan at the top that sucked air through the filter and up through the top of the tube. The paper filter would only allow the ball to be pulled about 6" up or half way but with the k&n the ball would shoot up and bang against the top. it was pretty damn amazing and i am a beliver

I did a similar test when I was driving from Nashville to Cookeville for college a few years back....

I found the K&N was good for approx 5 more mph on the top end during interstate driving when making the trip in my 90 Toy truck...

here's my comparsion, 89 cherokee...4.0 w/200,000+ miles
auto trans.

before filter change.....19.5 miles to gal@freeway speeds

After filter change.......22.0 miles to gal@freeway speeds

Rich

Actually according to several test results that I have read a brand new good quality paper filter flows as well or better than a K&N. The thing is that the airflow of the paper filter drops off sharply when it gets dirty and the K&N stays pretty much level.

Paul while I worked at a parts store, wee had the filter comparsion do hicky mentioned above. I could put k&n's together and still get more air flow than from a fram.
Rich

Check your throttle plate and MAF. There has been a few studies that a K&N will allow particulate matter of less than 2 micron pass the filter. This very small soil will coat your MAF and throttle plate.

Any Amsoil users out there that want to chime in?:D

all arguements of flow aside...the K&N is at least water proof. Not nessesarily a good thing if you hyraulic the engine but at least you can hose it off if you clog it with mud.
http://members.shaw.ca/steevil/Images/AG00547_(p).gif

Originally posted by Big Rich
Paul while I worked at a parts store, wee had the filter comparsion do hicky mentioned above. I could put k&n's together and still get more air flow than from a fram.
Rich

Darn those marketing people. Filling my head full of misinformation. ;) I did a little more digging and the K&N does flow better. I must have misinterpreted what I read before. :emb:

Like oldscout I've seen some stuff indicating the K&Ns let in some larger particulates that could cause much faster engine wear, especially after a layer of dirt builds up on the filter's oil coating (like when used in dusty offroad conditions). New paper filters filter about as well as newly washed and treated K&N's, but better once the K&N starts getting dirty. Paper flows less well when clean and even worse when dirty. However, the flow advantage of the K&N's could just mean more dirt is getting into the engine.

Admittedly there's evidence both ways, and there's also some dispute over just whether the additional particulates actually hurt the engine, since they're still pretty small.

Originally posted by steevil
all arguements of flow aside...the K&N is at least water proof. Not nessesarily a good thing if you hyraulic the engine but at least you can hose it off if you clog it with mud.
http://members.shaw.ca/steevil/Images/AG00547_(p).gif

its true. I burried my truck in a nice, soupy mud hole about a month ago. Took out the K&N and poured water through it until it was relatively clean. Put it back in and drove back to the entrance to do a more complete cleaning. It worked fine the rest of the day. I went ahead and did a *recharge* when i got home and its been good as new.
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