I was doing some research on oil filters a while back and ran across a web site that had a list motorcycle oil filter part numbers and a list of corresponding car oil filters. The person was saying that if your bike uses motorcycle filter X you should replace it with car filter Y because the car fitlers are larger and offer better filtration due the cramped size of the motorcycle filters. I don't know how credable the source is but I'll lokk for the page later and if I find it I'll send you the link.
