Oil filter OEM BMW or K&N

My lovely girl friend has a 2 door BMW 1997 325i. It's a very pretty car with 176k miles on it. We drove it all over and one day it hit me, when was the last time the oil was changed? She thought her parents maintained it, but after some digging the oil hadn't been changed in 1 1/2 years and possibly 30k miles. I pulled the filter out and it was worse than this, and just fyi BMW filters like these do it kinda often from what I have read.

Then engine had 2.5 out of the 7 quarts it is supposed to have. (poured the oil in a 4 quart jug to see). I have absolutely no idea how it lasted so long. It was a ticking time bomb. So after 6 quarts of oil and the seventh being sludge cleaner, the engine has no more ticks and runs very well.

I use K&N oil filters sometimes, a little cheaper than oem but they are quality.

I ran K&N oil cone filter on a LT1 motor for 3 years in FL and now for 5 years on my 1.8t. Never any problems whatsoever.

K&N oil filter / high mileage mobil 1 10/40 fully synthetic oil on my 1.8 16v.

I use mobil 1 0w-40 and k&n filters - when you buy a filter, get the oversized one that VW approved a while back - with k&n part number HP-3001 vs the stock HP-2005 - big ol' hoss filter but screws right on, takes an extra half quart of oil to fill it up :laugh:

Been using K&N filters on my 1.8t's with Royal Purple Oil. The two combined seems to leave very little to almost no build up of metal particles on my magnetic drain plug.

I've been using them for over 10 years and my motor runs like a top.

I got a Hengst Oil filter and two Mann Oil filters. I prefer to use K&N Oil filters. Right now I'm using a Fram.

K&N filter is not as good as OE and just about expensive.

Overpriced garbage. There is no proof that these synthetic type filters do any better job filtering than a high quality OEM or equivalent. I use OEM, for $13, at 10K miles pretty inexpensive and oil analysis is always good. OEM is best IMO.