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Is there any cons with a dry performance filter vs an oiled one? Is one better at repeling water, or is it just the slight difference in efficiency?
 

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Ive had nothing but the oiled in the past, mainly K&N and its a bit of a mess when you have to clean it and wait several hours before reinstalling it. Im in the process also trying to choose between the K&N and the dry filter system from AEM. The way it looks to me is that the dry lets more air in and its like which they say like 90% easier to wash. So goodluck
 

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Don't know the physics of it...maybe I'll look into it, but, I know from experience that most filters designed for "dusty / dirty" conditions are oil type. All the farm tractors I've ever used are oiled, even lawnmowers, for the most part, use an oil type filter. I suspect it is designed to attract and hold dust particles that would normally find their way through a dry type filter. Even my ATVs are oil type...

It is a bit of a bother, but, I always buy a second filter and can swap them out in minutes and then on rainy / cold otherwise useless days, I go hide in the shop and take my time cleaning it...let it dry for a month or two, oil it when I get around to it, etc. Wife can tell me "to go clean your filter" when she's sick of looking at me :D
 

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There is a growing sentiment that the oiled filters are mostly hype, and tend to do more harm than good. There are a couple of ongoing and lively discussions about this on bobistheoilguy.com

Lots of studies say different things, so who knows. I have gone back to the OEM paper elements myself after seeing some of the analysis findings related to silicon in oil due to low restriction air filters.
 

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I got the AEM dry one, and I'm buying into the whole dry over oil since I've had a few k&n's in the past and hated them. For really dusty conditions, you can get a pre-filter for the dry ones, but I didn't find the need for it driving a week in the desert.

Oh yeah, and what did I do when I hit some nasty silt and blew it all into my engine compartment? I took the filter off, kicked it against my shoe a few times, and put it back on - good as new =)

!c
 

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I don't know if they'll fully answer the oil vs. dry question in my lifetime. I certainly didn't intend to start another debate on it :(

Any "High Performance" filter is high performance by letting more air through. The only way that you let more air through is to increase the size of the air passages. You could increase the size (surface area of the filter), but, there are space limitations underhood and it is really hard to improve upon the total surface area of the paper filters that come OEM. The biggest improvement of the CAI systems is getting rid of the resonator and the convoluted air path.

If you let more air through, you let more contaminants through. Fact. Now, the big thing is the size of the particles and the amount (count). I've never seen a really good analysis of what is OK for an engine... How big / small can the particles be, how many and what time frame for damage to occur? Is .5 micron too big? How about .3? How small before the mass is so insignificant that most of it "blows" through the system without doing damage?

Oiled filters, if done properly, I would think, have the advantage of a "sticky" layer, that, could concievably catch more of the smaller stuff (law of averages, if a .3 micron bounces around in a .5 micron hole going through, it might stick). Can you muck up your engine by over-oiling or not allowing an adequate dry time. Yep. No argument from me on that.

Is the dry more convenient? I would definitely say so. It would flow more air than stock, but, IMHO, let more contaminants through than a properly oiled one. Are the maybe increased levels of contaminents of any consequence? Who knows for sure...not me, and I don't profess to.

I have the time and the technique for doing the oiled filters and have been for lots of years, kinda "natural" to me now, and I've never damaged an engine with them yet. I've had engines fail, don't get me wrong, but, directly traceable to the air filter / type? Nope. My son is still driving my old 96 Caravan with 222,000 miles on it. Doesn't burn maybe 1/2 quart between oil changes (6,000 miles with Amsoil).

Almost any "improvement" you're going to make has trade offs - you have to figure out which ones you want to live with :) I built high performance engines in the 60's (yeah, I'm old) - they didn't tend to last too long, but, boy would they run! High performance mostly is synonymous with high maintenance :D It's what I'm used to and I don't mind the time, gave up golf and working on my "toys" is therapy.

BTW, I have a prefilter for my oiled Airaid - yes, I can thump the filter clean in a pinch and the prefilter is water resistant in case I get splash ups.:cool:

I hope no one goes off the deep end - I'm explaining the logic I used to the 'fella that was in a quandry :D For the safety of the world, I hope there aren't too many people that think like I do!:eek:
 

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I'm also curious about this topic. I'm using a K&N CAI right now but am not keen on the quality and intake noise as well as where the MAF sensor is relocated to. I saw a picture of someone's 4.7l XK here that was using a dry filter CAI that utilized the factory resonator and only replaced the zip tube and airbox, but didn't notice the make of that kit. I like that idea since it keeps the MAF in the stock location. If someone could post a link to that thread or pic I'd appreciate it.

I also have a TrueFlow filter in my garage for the OEM intake system that I'm thinking about going back to so I can start running regular gas again. Anyone else have experience with the TrueFlow drop-in products?
 

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Discussion Starter #8


Is this the one you are talking about? This is what I am looking at getting, its an aFe CAI and they offer it in both a dry filter and an oil filter, and that is why I asked the question.
 

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BigRed, that's the one, thanks for finding the pic for me. I'll go with the dry one if I get it since I don't want to deal with the oil of a K&N anymore. I also like the air box on the AFE better then the open "box" of the K&N.

Update; Just ordered mine from Autoanything, they're on sale so my total order was $253 shipped.
 
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