K&N Air Filter

[Team Jeff]

Reply in red,

That is some interesting data. And I would agree, if you are going to use your LR3 as a dedicated off road vehicle, or if you use it in the dessert, etc., where max dirt filtration is key, I would not use a K&N. Also, you left out the key summary finding. The K&N does indeed flow more air in a normal environment. (See below) Sure it flows more air. And no filter would flow even better!

However, that constittues likely a tiny statistically insignificant portion of LR3 owners. Sure we take our LR3 off road every so often, but most of us don't have a constant stream of dirt/dust blowing into the air intake. There IS a constant flow of dust entering the intake in almost every situation - it's a matter of quantity.

Conversely, what we do have, is a constant stream of normal air blowing in. The results of the very study that you point out support the fact that the K&N had "less restriction to flow." As your study below states, it is a tradeoff between "dirt capturing ability" and maximizing air flow. (By the way, if you are worried about your engine because of the differential between the dust/dirt that the K&N may pass as compared to what the OEM paper filter will pass. . .I want your life, as that worry is really really easy to deal with.)I certainly don't worry about it, no need to. No K&N's on any daily drivers or offroad cars. Although I do admit having K&N's on some specialty cars, but this is because there are no other good alternatives- Roush 8-stack injected V8.

The text below is the summary findings from your article:

"The Flow Restriction response curves for each filter have the same basic shape. However, note how the AC Filter, which passed the smallest amount of dirt and had the highest dirt capacity and efficiency, also had the highest relative restriction to flow.The less efficient filters correspondingly had less restriction to flow. Also from the same test - "The other filters, most notably the oiled reusable types, had an exponential loading response before reaching maximum restriction. These filters had a lower initial restriction, but they became exponentially more restrictive under a constant flow of dirt.

This runs counter to the “myth” that oiled media filters actually “work better” as they get dirtier."

This illustrates the apparent trade-offs between optimizing a filter for dirt capturing ability and maximum airflow."

 

[blackforestham]

I've quietly sat on the sidelines with the K&N issue. Interesting. I use the K&N for street use where dust/dirt/micro-debris is less of an issue. I know how to re-oil properly. Have never had any issues with numerous vehicles. I ALWAYS switch back to a paper filter when I am going offroad or where dust will be an issue. At the end of the day on the trail, I can bang out PILES of dirt from the paper filter and be good to go. I've also never realized any performance gains with a K&N filter on a vehicle - with the exception of a well prepped Stillen equipped Nissan - she was funnnnnnn!

 

[roverman]

I can't for the life of me figure out why anybody would use one. To gain that extra drag-race-winning 5 HP on our 6000lb pigs? To save $50 over the next 100,000 miles? To have the joy over stressing out about whether you applied too much or too little oil? To wonder (justifiably or not) if you're killing your engine or if it was your fault that the MAF took a crap? It honestly makes no sense to me.
$.02

 

[schafari]

You want to hear what sold me initially? Actually it is not the HP gains at all, that is not even a consideration. As funny as it sounds, what sold me was my Shop Vac. I got a new Shop Vac and was using it for the first time. I had the original cheapo dry filter on it. (paper) Well, I also bought a fancy upgrade filter for it which was more of a fiber/cotton type. It was a high performance filter for the Shop Vac. I didn't expect much difference. OMG was I wrong. The difference in suction was night and day. It was unbelieveable.

Anyhow, since that time decades ago I have been putting K&N panel filters in all my vehicles. Off the top of my head that is over 16 vechicles all with K&N in them for years with not a single problem ever.

Like I said, it sounds funny but man, a simple filter change on a Shop Vac got me thinking about the least amount of air flow restriction is a good thing. . . Oh, and I kind of like the idea the that I am not replacing filters every 10k which I would do. No worry about getting wet, etc.

Again, on these boards K&N or not is like a religion. Unless you are totally new to the topic. . .there is no way someone of the K&N religion will convince a non believer and vice versa. Politics, ending pregnancy, ha, that isn't anything compared to the K&N debate;-)