One important factor which seems to be overlooked in oil filters is the anti-drainback valve. Several brands I've tried which supposedly had anti-drainback protection actually didn't do it. Because of the horizontal position of the oil filter on Volvo engines (especially the B18 and B20), all the oil drains out of the filter back into to oil pan. Then when you start the engine it takes 5 to 10 seconds for the oil light to go out. It drives me CRAZY to watch that oil light stay on for more than a second or two! I just think about my rod bearings grinding away. Even the Bosch filters I bought at Trak Auto did this. I've replaced filters with only 100 miles on them because of it. Now I've started using Toyota V6 oil filters on my car. They're smaller than a Volvo filter, but so far all the drainback valves have worked, and even if they didn't, the smaller filter would fill up faster. Personally, I'm not that impressed with the amount of filter media. I change my oil every 3k and it doesn't get dirty enoug h to clog even a small filter. As for brands of Volvo filters, I agree that Mann is best. I think they actually make the original Volvo filters...they look identical.

Brian