Things like the TP filter work off of a sheer volume of filter media. It passes the oil from the top of the roll to the bottom. Over 4 inches of solid filtration. Its sound and easy, simply because it has so bloody much media. And just like a bypass of today, they only filter a small portion of the oil at a time. You can't really pass much through toilet paper at a time.
I can't imagine any septic-safe TP would be good as its designed to break down. I've been told by a few people who use it (I asked around after they mentioned it at the other forum) that "John Wayne" TP works best. By that they meant the no-comfort, rough but tough commercial stuff. Go to 99% of public restrooms. Thats the stuff. The added advantage of it is that its not poofed or fluffed, like, for instance, Charmin. More density of the filtering media.
I'd really recommend Schaeffer's Oil. They are a hair above Amsoil in quality and they beat them on price in some cases. Its harder to get ahold of their stuff, but its well worth it. I use Supreme 7000 in my cars, diesel and gas. 7000 is a blended oil, but it still beats the crap out of every other oil I've seen it go up against. I saw a surface-film strength test conducted and even participated. It make stuff like Rotella T Full Synthetic, Mobil 1 Full Syn, Valvoline Full Syn, and even Royal Purple look pathetic. We picked up a crate of 6, 1 gallon containers for $90. $15 a gallon isn't too shabby for something I've seen test so well.
Another thing with Schaeffer's, since they do tailor to the OTR crowd, usually you can only get bulk. 6 gallons for instance. No big deal, considering you can just hang onto it until the next change, which, with it, will be a long way off.
You should check out their website. They have a huge line of lubricants, and some specialty cleaners and fuel treatments along with that. A lot of it tailors to diesel, but gas stuff can be found, and Supreme 7000 and Supreme 9000 are both compatible with both, 9000 being the full Synthetic.
I've not heard the greatest things about the Bosch filters... Definitly heard less bad about them than FRAM, no question there. Best I've heard of, and use, is the Purolater PureONE line. Best full-flow filters available. They are like a mini-bypass filter. They clean much smaller particles than other filters. The question with that, however, is whether they will restrict themselves from mega-filtration or not. I've never seen/heard of it happening, but thats with a 3-5000 miles filter change interval. I know my car loves the thing.
Just checked their application guide. Doesn't look like they have them for the 1.6IDI or TD. I know they don't have one for the 1Z TDI, but have yet to check the others. Though, I do know there are plenty of other filters that will fit. They just don't have near the bypass valve pressure. Here's their Purolator standard filter.
http://www.pureoil.com/smartlink/?partnum=L30257
