K&N air filter now available for latest generation Prius

I don't think much dirt if any will go through due to a bit of water


Well, when I think, I think as you do. But I've seen sand pulled through several K&Ns from off-road bikes... and also through foam. I might've misread your "water + K&N" comment, so no harm done I hope.

Not that water through a K&N is the end of the world because, as you say, when the water comes through, you have bigger problems than the silt it brings with it.

Think about it- dirt stuck to the oil will remain stuck while the water simply flows past

Yeah, but here go the both of us thinking again. (insert laugh track here) Even when oiled, there are still pores. And I think the nearby dirt particles (smaller than the pore size) will let go of the oil and follow the water. These particles are (again, I'm "thinking") usually stuck to the oil and, absent water gushing by, they remain there until cleaning time.

Also, there are several variables to be taken into account, like how well is the filter element sealed to the airbox? I always put a ring of waterproof (thick petroleum jelly-like stuff) grease on the sealing band, but it's always possible that some of the silt got by the seal. I don't think this happened, but that puts me back to the problem of "thinking" again.

Anyway, I'm not really trying to disagree with you, but I've seen what I've seen. Nor am I trying to trash K&N. I really don't know how much "street crud" will get through a K&N, but I never liked them on off-road bikes because they spent so much time in extraordinarily dusty environs... and some stuff got through.

Pleated paper is still the best filter media, but water will kill it.

Still haven't heard anyone say "better gas mileage" and "K&N" in same sentence.

GeronimoPFudgemuffin

 

<div class='quotetop'>QUOTE(slow95gt @ Nov 15 2006, 05:21 PM) [snapback]349878[/snapback]</div>

Get a K&N to replace your brain-filter. It is clogged :angry:

 

I've driven 80k with my K&N. I drove the first 15k with the stock filter and the K&N has no effect on mileage(160 mile commute-round trip).

I clean and re-oil it every 20k(hard driving-country roads, stop and go, 1000 ft pass every day, 75-80mph). The filter traps a lot of junk. The inlet to the manifold side of the air cleaner is spotless. So I think it works OK IMHO.

 

I had the opportunity to tesk a K&N air filter on my 2005 and put it on our chassis dyno. The results were about what I expected. There was basically no additional power gain regarding HP/Torque compared to using the factory air filter. I did 3 seperate runs and they were all within 2-3 rwhp/tq between them. These HP variations are typical of a dyno and basically shows that there were negligable gains if any to be had.

I should point out that the filtering ability of the oem (Toyota) filter is "probably" better/superior over the less porous surface of the K&N filter. If one puts A LOT of miles on their car and does not want to spend the money for the factory air filter then I guess the K&N would be a decent substitute. The biggest problem with them that I have seen and has been mentioned is that people tend to over-oil the filter. This oil gets deposited on the very fine MAF wires and can cause other issues. If you chose to use the K&N I would LIGHTLY oil the filter as per the directions!!

In other high performance applications I have seen the K&N filters provide impressive (over 10hp gains at the wheels) on our dyno but the Prius is NOT a high peformance type car. If you look at the intake of our car you will see that there are a lot of restrictions already in place not to mention the carbon filter that will restrict air flow.

In conclusion I personally would stick with the oem filter and call it a day!!