idk, to each their own, but I run a K&N on my pro truck, idk if it pull as much or more than my 7.3 does being that it spends it like at 7800 to 8k rpm, but i had to run one of their diapers on the outside of the filter so it would help to pick up stuff so it would quite clogging the air bleeds in the carb. Yes I realize, somewhat comparing apples to oranges, but what im getting at is the material they use for the filter media without a doubt does let dirt, dust, whatever through. I'm not a huge fan or K&N, but there isnt much better out there for the application and they pay contingency on occation. I also love my 6637 for my 7.3!!