I found out yesterday that all stock air filters are not the same.When I bought my 3500 it had a fresh service done ,wrong oil filter but air filter was new.Yesterday I was cleaning truck & wiping off air box & found the restriction guage almost pegged.I reset it & went for a ride,ran it up a few times with hot juice on 2.Checked guage twice both times was 3/4 in red.Went home & put the original filter from my 2500 in with 1000mi on it & it never moved guage from green.I don't know what brand it was but there is a difference. I'm still deciding which way I'm going with new air filter uni like my 2500 or AFE.

Bob ~ guess I'll express my ignorance. I don't know how to read the indicator. I've read the manual ~ but wondering if it indicates/operates at idle? fast idle or w/the eng not running?

The way I've always thought it worked,is as the air flow is restricted the vacuum on the engine side increases pulling a vacuum on chamber & plunger/indicator moves.It stays there till you break vacuum on guage with reset button.It stays at its highest mark till reset running or not.If that makes sense,maybe.

Bullseye! I mean thats right! The system works of off a vacume in the box! Th indicator can be checked at any time, and it stays in place until the button is pushed to release it or a vacume sucks it in some more.

Depends what you want, flow or filtering http://www.dieselplace.com/forum/smileys/Big Smile.gif
or... The finer the filter the sooner it blocks, Ya takes yer choice.