Newer thought i would ask that question but here it is,
does it matter/any/much difference on all the engine oil filters there fit a P38 Petrol? (Spin on type)
Read somewhere to always use OEM as they have a non return valve/function built in there keeps the oil in important places for the next start, is that true?
To name a few: Coopers, Mahle, UFI, ****part etc...

Clearly there will be a difference in quality between the different manufacturers. Not sure about the non return valve thing though. I have always used Mahle. I believe the are a good middle of the road product and priced right. Some of the professional mechanics on here will have a more experienced opinion.

I have no problems with any well known brand, "Fram" is another trusted make. I personally won't buy a reboxed/renamed filter unless it has come from a main dealers.
Now if someone wants to supply their own filters/oil that up to them...

****part......name says it all most of the time, but I believe some ****parts are OEM so you must be careful when buying..