I would like to use a filter that flows fast with low restriction. It will be used on my boat with straight 40 weight oil. Right now i am using a Purolator Pure 1, and i feel it has too much restriction for the thick oil. I used to use a FL-1A, but they are getting hard to find for me. I also heard that the FL-1A are the same as a Pure 1. Wix/Napa gold seem to have a lot of restriction also from what i have read. What is a low restriction filter? Supertech? Fram? Purolator premium plus?