There is an American website where a chap buys a huge variety of oil filters and chops them up on a bandsaw to compare the filter paper area, non return valves etc. There *are* noticable differences between OE supplied filters and copies, in terms of whether or not they have a non-return valve and in paper area. I very much doubt that if I and you both bought identical cars and ran them for the same mileages, one using OE filters and one using pattern, whether we'd be able to tell a difference. Mainly because there are just far too many variables involved, and because most cars get sold or die of body rot before the engine fails. You might find a bit of power loss on a dyno or a difference in the health of the engine on a strip down however...