Originally posted by Tony:
Josh, K&N claims their filters are superior to any paper filter in flow or filtering characteristics. Read this then decide who to believe. K&N facts I know they claim that, (I have read it before) but it is only true until the filter starts to clog up with dust and then it leaks dirt like a seive. You need to clean and re-oil it every 10000 miles or less to keep it from leaking dirt, at least a paper filter has the property of clogging up and making you notice that it is going to need changing. I have firsthand experience using a K & N filter in a 1991 Ranger 3.0 engine in a fairly dusty agricultural region putting about 60,000 miles on it in 4 years. I ran it half the time with paper and half with the K&N, and if I didn't clean the filter every time I changed the oil I would notice dust start to build up in the intake pipe and throttle body that I would never get with the paper filter. I didn't get much performance increase out of it either. It just wasn't a bottleneck in my case.
If you are noticing that your K&N doesn't get dirty as fast as your paper filter did, that means that your paper filter is doing it's job and your K&N isn't.
K&N's are fine if you maintain them well, but a lot of people don't. Just because it doesn't look dirty doesn't mean it isn't. Sorry, I'm skeptical of what manufacturers websites leave out. As an engineer I know all about yelling loud about your product's good features and whispering or shutting up about the bad.
Amsoil\'s filter Filter efficiency compared using SAE J726C test procedure The best way to get around flow restrictions is to make the filter bigger, not sacrifice flow for filtering ability.
