If K&N are so bad why do 220HP $40K aircraft engines have them on from the factory?

If K&N are so bad why does Van's Aircraft (largest kit plane suplplier in the world) recommend them for all their planes?

If K&N are so bad why do all Rotax aircraft engines (65 - 115 hp) come with them installed from the factory?

Buy a K&N, put it in your truck, and forget about it it for 50K miles, or until your filter minder starts to move. Wash it, oil it, and do it again.

 

I could make a hill of beans to me what someone puts on their truck, My point was warranty related and I will argue until my last breath about it being voided by having a K&N on your truck.

As stated earlier no harm no foul, just dont want anyone to get ramrodded by a cruddy dealership.

 

"If K&N are so bad why do all Rotax aircraft engines (65 - 115 hp) come with them installed from the factory?"

Because engine life is so short betwen required overhauls that it doesn't matter. The Rotax seems to have 1000 to 1500 hrs between overhauls, which at 60 mile per hour would be 60k to 90k miles in our trucks. If you don't care what condition it's in at that point then use whatever. I care though, and it's so common to see high silicon (dirt) levels in a used oil analysis from people using oil filters that it's the first question asked. Usually that's the problem.

That being the case, I still found a problem with the stock Fleetguard filters and the stock airbox after a recent change. Usually I see the filter minder drop a bit and when I didn't after a recent change I looked a little closer, and found dust around the clean side of the filter on the side that doesn't have a clamp. Short term I put a bit of silicone grease on the rubber seal of the air filter, and removed the large inlet flexible hose from the top of the airbox so that I could more carefully instal it. It slid on easier, and the filter minder dropped a bit like it usually does, but I'll add a small clamp soon.

 

Diesel Power mag did a comparison recently, results published in latest issue, and found there was little difference in performance between the stock air filter and several after market installations. The truck they used was otherwise ALL STOCK. I believe they also comnented that paper filters typically filter smaller particles better over a longer period of time than oiled filters. I have seen other testing results with same comments about paper filters. I have a K&N on my motorcycle (it came with it installed) and found that if I am not very careful about re-oiling it just right, I actually INCREASE the amount of restriction (IE: too much oil). Also personal observation, Aircraft engines operate in open air at altitude (except taxing, takeoff and landings of course)... far less dust than we see here on the ground.

 

I remeber somewhere that I can no longer find were a independent study was done for the Government and Donaldson won with a paper filter not only for filtration but also performance??? Has anyone else seen this report? It was very detailed and scientific. Had nothing to do with any company.

 

Didn't realize this thread kept going so I posted jonesey's post which pretty much should sum it up for you moss act guys. It's post #14 of this thread. Yah if a person has an agenda and plenty of money to waste you could win just about any lawsuit, O.J. case comes to mind.