Anyway the engineer that was cutting the filters open and photographing the results reported that the Frams had less than 40% of the filter media area of most of the other filters tested and they used a cardboard anti-drainback valve that didnít seal well where the others all used metal or a heavy plastic. The engineer was not kind on his Fram findings and said so which ended up with Larry Bossidy the ceo of Allied-Signal filing a lawsuit against the engineer and ended with him being forced to remove the website at that time, big money and big lawyers.k the next oil change I will give them a try. Just a little info, do with it what you want.
The reason he lost was that he stated unfounded conclusions such as to the ability of the product to serve its intended purpose. The quality of the filter media. Things he didn't measure.
Others succeeded by cutting filters open and only stating observed fact: number of pleats, total surface area, weight and thickness of filter media. Material.
If paper is good enough for the filter media then what is your opposition to "cardboard" end caps or even drainback valve? Are these items failing in use?
If one only knew oil filters based on what they find on the internet one would be lead to believe the Anti-Drainback Valve is the singular most important component. That for some reason at all costs it positively must prevent oil from draining out of the filter. As contrary as it may sound, that is not its purpose. None form anything close to a perfect seal. Just fill an oil filter and lay it on its side. It will be empty in an hour.
The purpose of the anti-drainback valve is to prevent a pressure backwash when the engine is turned off. Some engines get a shockwave back through the oil passages when oil quits being pumped. This shockwave would backflush crud captured in the oil filter. The anti-drainback valve only serves to minimize this momentary backwash.
In the What Is Old Is New Again we see a resurgence in the cartridge oil filter. A pure filter element one doesn't have to cut open the can and destroy the filter to see the media. And one that 1) doesn't have a bypass valve or 2) drainback valve. If the media collapsed in use then one would see. I like cartridge oil filters.
Bugged the heck out of me that my Subaru Outback oil filter is mounted open-end down. But I bought the car anyway. Now that I've had it nearly 4 years my worry was for naught. Even the OE Subaru oil filter is nearly dry about 5-10 minutes after the engine is turned off. I suspect it drains out the center, in the normal direction of oil flow. My concern was the mess it would make when removed.
A side effect is that the Subaru oil level changes more from hot to cold than any engine in recent memory. Might be 1/4" over FULL in the morning but if checked while pumping gas be comfortably under FULL. Is hard to know exactly the right time to check. So if it is that hard I conclude it mustn't matter else they would have made it easier.