There is alot of other stuff in oil filters...
Pressure relief valve... they have different pressure settings as well.
Anti Siphon Valve... anti drain valve... stand pipe...
The media (paper) can be treated for different properties, long life, finer filtration....
Worked in filtration for 10 years, TJ filters, British Filters, Wix filters...
Personally for my Jeeps I buy Mopar filters, for the couple extra £/$'s it really isn't worth messing about. M&H, Mahle are excellent aftermarket filters. I have seen and tested a lot of lesser brands that in short where crap and didn't actually filter.... Oil and filter are one of the few things that look after your engine, I wouldn't mess about... also do not over change your filters, they need some muck on them to work properly, when new they are more 'open'... if they filtered perfectly from the start they would block up very quickly.
Also worth noting American made filters have the pressure relief valve at the top of the filter so when it open (cold mornings) the oil doesn't have to pass all the dirty media, possibly picking up crap before by passing the filter cycle....
So in short, stick to the filters that are listed, unless the manufacturer can check every other detail in the filter is the same...
Hope this helps, Maf
