I put my K&N drop in filter in my stock 04 5.3 about 18K ago, and while I think i noticed a little better mileage, i think i noticed a little LITTLE bit of lose on the very low end grunt.
but recently i have been hearing about bad things the filter is doing to the engine, and it not filtering good. is it true.
I have had no problems with the filter in the 18K ive had it.

 

think about it like this:

if you are getting more airflow in because you changed your filter, that must mean that your filter must be less restrictive, correct? now: how do you make a filter less restrictive? (bigger holes)

the K&N won't filter as well as a stock paper filter, but it does filter adequatley. The purpose of the oil on the filter is to make up for the more pourus surface area by using the filter to trap the dirt as it passes with the air, of course over oiling the filter will cause excess oil to get sucked in the intake tube, and some will get on the MAFS, which will throw that off, so you then have to go get some MAFS cleaner and get that right...etc...etc... etc.... it's all calculated risk, you have to decide what is acceptable

 

It's more porous, yes, but the oil coating makes up for the bigger pores. I'm not saying it filters just as well as a paper unit, because I have not done these tests.
I guess you could call K&N a see what they have to say about it.
I just really think a properly cleaned and oiled K&N air filter will filter the air just as well as a paper unit will. IMO

Jim

 

I've been using K&N for years, but I've been thinking of switching to TrueFlow. K&N and several others use gauze, which will deteriorate over time. TrueFlow uses foam which sounds strange, but they claim it filters better than both gauze and paper and that the airflow is more than adequate. It won't deteriorate and doesn't require oil. I think all it requires is to be cleaned with running water. If anyone uses TrueFlow, please chime in. I'd like to hear what actual end-users think about it.

 

I agree with you Jim, but I just was trying to give a open minded factual statement. Personally I have a Volant system in mine, I don't think it's any better or worse than the K&N, just that the box design is different... benefitial or not

 

i had a TRUE FLOW before i got my turbo, i really liked it but SOTP couldnt tell the diff from a K+N FIPK. But as for filters heres a thought. Pick up a piece of paper and try breathing thru it, then pick up a pair of panty hose and breath thru them, I say an easier breathing filter media is better for the engine, just do the proper maintainance. I have a K+N on my Lawn mower!

 

Yeah, me too. The Volant just looks better under the hood. I too don't think it works any better that the K&N kits.
The ram air is just hype that makes me clean my filter way more often!

Jim

 

I have a true flow filter on my truck now and it does use oil. I also like that it retained the factory airbox and is a truly sealed sytem. On the true flow web site there is a pretty informative video that compares paper, gauze, and foam filters. ATV's and offroad vehicles have been using foam for a while now and the one on my atv is dirty as hell but when I remove it the airway behind is still really clean. Can't say that about the truck I used to own with the K&N. When I removed it for cleaning I could always see dust and grime in the intake tube.

 

I had a foam filter on my Ford Contour and it deteriorated badly after about 50,000 miles. I can't remember the brand name, but it was the popular green foam intake that the ricers use...