[Moderator Note - this is starting to sound like a religious argument, i.e. no final answer. Time to form your own opinions and move on. Officially the end of the thread. Feel free to continue off-line ds] Steve, I do respect your opinions and your knowledge, But may I suggest you or anyone call Bosch technical at 800-521-5462. They will explain the operation of the Anti-drain Valve and the By-pass setting if no one wants to take my word on it. . We could bebate this all day. But there is no check valve like in the fuel pumps and there is no restriction on oil flow going into the filter or coming out. These above things I'm talking about are safety features that are built into 50% of the filters depending on design. The Mahle filter I bought from DMC Houston that Mike mentioned have the same built in features. You can spend $15.00 on a filter or $5.95 on the Bosch I offer to the group. It may not have a more exotic name, but I'm looking for safety and function and price. Bosch fit the bill for me on all and they can be found almost anywhere. The Anti-drain back Valve is on the back side of the operation to prevent oil from draining back into the engine when the engine is shut off. If you crank the engine with out oil in the filter, it will take about 5 seconds for the oil to circulate. After many times of cranking, the upper engine will encounter more wear and damage over time. That's all it is, nothing more. Nothing high tech. It's a rubber gasket. The By pass setting of the 72150 Bosch filter that I sell is 27-35 lbs. This means that if for any reason the oil filter got clogged, the by-pass would open and allow oil to the engine instead of harming it. If you didn't have this then the filter could build up pressure and burst. These are safety features used in over 50% of the filters. If you don't want to use the safety features on the filter that's up to you and others but I for one will take advantage of them. As for the Teflon, I have used it in the oil and manuel transmissions for years and have had no trouble. When I was inspecting one of my cars that had it in, the tech was wondering it took so long to for the engine to heat up to get the 02 reading he was looking for and ask me if I had teflon it in the engine. I said yes and then he understood. Teflon does nothing more than reduce friction like oil but does it better. If used as directed I have never had it had a problem. Good luck John Hervey www.specialTauto.com P.S. A lot of cars have a pressure regulating valve built into the engine.