I don't know much about filters but a friend says Napa gold filters are some of the best. I have been using the k&n because of the nut on the bottom makes it easier to change. But they are very expensive! I bought a old beater truck to haul wood and stuff and it had a purealator on it and the oil pressure was a little low and didn't come up much even under a load. I changed the oil and filter now the oil pressure is where it should be and with throttle it goes up. Was it the old oil or the filter? The new filter I used on the old beater truck was a Napa gold.