Originally Posted By: Bluestream
The filters are smaller to save costs, and make room in a tight engine bay. A larger filter will generally be able to filter more oil and for longer, but it all comes down to the sq inches of paper inside.
Ya. I think, too, the engineers 20 years ago used the biggest filters out of habit. But before that there was a lit more people still using straight weight oils rather than 5W-XX.
May have something to do with it.
I like bigger filters though.