I personally used them many times on my quads, and saw with my own eyes the dust trails left in my intake. I've read many times on the powerstroke boards about 7.3 guys using them and finding the impellers chewed up from sand.

 

How much sand do you have too drive your truck through to get to that point? All things being equal, quads LIVE in the sand. See where I'm going? Evem though I live in a sandy, windy area, I've not seen scoring in my Mustang carb (that's way up in a teardrop scoop sucking air).

How much sand was my truck eating when a month after I bought it, a shop tapped my OEM filter on the deck and there were 2 huge piles when they were done? Dirty filter, mud caked frame, smoked turbo, previous owner was pretty tough on my truck.

Quads to diesels is apples to oranges. With that in mind, were the filters failing on those 7.3s, or were they not maintained properly? How many times have we read keyboard commando parts failure reports that were actually maintenance issues?

 

IMO, any sand is too much sand, would you agree? My quad only had the piston pulling air in, I'd imagine a turbocharged motor of any variation is going to suck even MORE in right?

I simply made a filter switch to a foam filter UNI on my quad and my issues disappeared, even running an open air filter box with no lid. No sand made it past my UNI's.

FWIW, I would clean my air filters on my quads after every single ride/race. I tried a variety of different oils on my K&N's as well to try and eliminate the sand issue. I would remove my air intake boot (boot from filter to carb) and clean that out extremely well. I'd install the K&N, have a 5 lap moto, come in, wipe a clean white cloth through the intake boot again and pick up dirt, EVERY time. One season of that cost me a fresh rebuild on my 400EX. I made the switch to UNI's and never had a problem again. UNI's were also 1/2 the cost.

Regardless of how good they might be for our application, I know the proguard 7 dry filter I use, has 7 layers, and K&N's have 5. Which would you choose? I've actually thought about going back to a stock filter just for peace of mind.

7.3's probably weren't the best example anyways, since their stock air filter box sucks factory.

Whether the K&N can even filter as good, I still wouldn't buy it simply because I prefer dry filters for turbo diesel applications. There have been quite a few cases of clogged up MAF's from the oiled filters. Whether they over oiled or not, why risk it? Anyone can plop a dry filter in without having to worry about the filter tacking up, or if there is enough oil, or too much oil on it etc...

Just my opinion!

 

I'm not looking for a new filter, but you know how much I hate blind rumors. Not sure about layers in my Airaid but the back side of the box is always clean and the compressor wheel always looks normal.

 

Agreed, and in my case it is not blind rumor, it is first hand experience, which then backed up all the rumors I had heard.