I think they are made by champion labs, which means e-core junk.
Here is a list that i found for who makes who.
*Purolator (Arvin Meritor)*
Purolator premium plus (nitrile adbv)
Purolator Pure One (silicone adbv, different media)
Maxlife Valvoline (some)
Quaker State (less media)
Advanced Auto Total Grip. (less media)
Pep Boys Pro Line
I'm not sure that list is right. If you look at the Clarcor site, it says it makes Purolator.
Clarcor owns Baldwin and i took a tour at the Gothenburg, NE(Baldwin) plant, and you could see how well they are made. It'* nice to be able to stop at places to see how the things you use in your daily life or work are made. One of the funnest tours i went on was in Oakland, CA at Caterpillar, GOD they make some BIG THINGS.
rods789 at sbcglobal.net
PB 14.474 @ 96.248 PB 60' 2.168
180 therm k&n filter
3.33 pulley 3" cat back exhaust
custom solid front motor mount
custom 6" (BIG) intake
___WCBF '06, '07 survivor___