Interesting... Amsoil (AFE) seems to have modified their marketing and is now claiming significantly better filtration than cellulose.
But here's some real-world test results of several filters:
Also interesting, related to the "how much is 'good enough' question:
"Best" was the K&N at 0.231psi
"Worst" was Napa paper at 0.249psi.
Having a hard time finding the charts that used to be posted.
I found one that showed the Amsoil to be equal to quality cellulose, but it appears to be referring to the 2-stage foam filter.
Anyways, a couple of years ago, Amsoil's marketing materials included a very good chart comparing 5 or 6 filters, including K&N, AC Delco, foam, and a couple of other "paper" filters.
The graphs showed the "paper" (cellulose) being the most restrictive, but the best filtration. The Amsoil (AFE) came in below paper on filtration, but significantly higher than K&N... but with marginally better flow than K&N.
Could be that those charts were removed because Delco wasn't happy about it? I don't know.
I'm going back to OEM after I use this AFE for a while. The OEM Denso is literally 3 - 4 times thicker in my opinion. I'm looking the for best filtration, I'm not worried about performance, if I was, I wouldn't be driving a 2.7L or even a 4.0L 6 for that matter.
Conclusion - Stick with OEM Denso Air Filter. Thanks for the links. Good tests, I've been to BTOG's site a few years back. . . Bums me out about the Napa results. I did a ton of research after I bought my Tacoma regarding which Oil Filter to use and I came to the conclusion that the Napa Gold by WIX was the best / and easily available. . .
Not falling for the AMSoil hype anymore though. I've been using it since my truck was new. Just changed my oil on Sunday after 5700 miles - hate going that long but it was the first chance I've had to get to it - 5700 MILES - AMSOIL was JET BLACK. This is the AMSoil that claims 25k between Oil Changes - Well I'm calling BULLSHIT!
Done with it, switching to Mobil One, at least I'll save $2 / Quart.