1/2/2012 12:01 PM
All engines require a certain air flow. While there are inner filters offered, if the manufacture sent them to you with only the large outer filter, then I would stay with that set up. If they came with an inner and someone removed them, then by all means install them. Always following the manufactures recommendations will save you in the long run when it comes to warranty issues. Some things I like to step up a little like service intervals and using better lubricants, but I never consider taking a lesser route. Hope this helps you with your decisions.
Regards,
Henry