Thought I'd pass this along. Sorry if it's a repost.

This comparison is for air filters for a Chevy Duramax diesel, but I found it interesting nonetheless. Make of it what you will....

Air Filter Test Report

 

Thanks for the post. That was good info. It once again proves that K&N filters suck (without filtering).

Are Toyota OEM filters made by one of the other manufactures? WIX?

 

And I just spent about $70 on a K&N drop-in filter. I wonder if there are other test results out there that will validate these results. I did notice one serious problem with their graphs...some of them properly start at zero, others start at a higher number. When a graph is presented that way the differences represented in the graph are misleading. So how many of you are going to go out and buy an AC Delco filter tonight?

 

Just put it up on ebay and get an Amsoil filter. You will still come out ahead.

I got $50 for my 5VZ K&N drop in filter.

 

I thought about getting the Amsoil filter but I have heard some fitment concerns about the ones they are selling now for 3rd gen 4runners.

 

what about using a k&n with a prefilter?

 

I switched to a OEM replacement Puralator from my K&N because I was concerned about my MAF sensor and that was more important than the minor HP gain.

 

Never had a problem with mine...

 

You could do that but I think it would negate the free-flowing properties of the K&N. Zero sum game...

Basically the conclusion is there's a tradeoff between filtration ability and flow (i.e. you can have better flow but more crap will get through).

I agree with X-AWdriver, the performance gain offered by these oiled filters is so miniscule that it's not worth risking your MAF. Especially when you can replace the OEM filter for $20 a year....

 

Gadget, Any input on this study?

 

Here's another:

http://www.gti-vr6.net/library/engin...lter_test.html


I think the real issue is how much the flow drops off as the filter accumulates dirt. The K&N types seem to continue to flow better than paper. Maybe after a point they allow more dirt through?

Another big consideration is the MAF problems. I've seen many more mentions of problems with Amzoil filters than K&Ns over the months on this board. Is it just that Amzoil users are zealots who religiously over-oil their filters?... ;-)

If the K&N only works as good a paper filters I would still go with it, I put in 2 or 3 filters a year in my 85 until I put in the K&N, so they K&N saved me a ton of money.

Might just try the Amzoil filter.